diff --git a/core/README.md b/core/README.md
index 07f0e7a..49136ae 100644
--- a/core/README.md
+++ b/core/README.md
@@ -190,6 +190,16 @@ differently from the other bindings:
   matrix reads the binding's `scripts/ldd-fixture.sh` for the source suffix, the
   comment forms, a test file's name and two linter configs per row: one that names the
   file-length rule and one that names a rule of a similar name.
+- `setup/golangci.yaml`, `setup/ruff.toml` and `setup/eslint.config.ldd.mjs`, the
+  recommended linter configurations, are core templates rendered into every plugin,
+  so the generic plugin carries all three for the languages it reviews. Each enables
+  the linter rules the bindings' routing tables route to a design rule, at the
+  limits the rules name, and takes the file-length limit from `{{.FileMaxLines}}`.
+  Each names its linter on purpose and carries a `residue-exempt:` marker. The gap
+  linter's threshold line names the file and rule that would hold a limit, and the
+  `ldd-lint` matrix checks that the file sets that rule at the scalar's value; when
+  `golangci-lint`, `ruff` or `node` is on PATH, the matrix also has each tool check
+  its file.
 - `scripts/check-repo-brain_test.sh` is a core template whose cases read one include,
   `scripts/repo-brain-fixture.sh`: the fixture rows (marker, code file, second
   package, sub-project) for every language the rendered gate's adapter serves. The
@@ -220,11 +230,11 @@ Hard residue: none. No plugin-name or command-prefix literal, golangci
 reference, source-file glob, nolint directive, scalar word or retired Go idiom is
 left in core/.
 
-Soft residue by token (130 lines):
+Soft residue by token (131 lines):
 
 | Token | Lines | Files |
 |---|---:|---:|
-| interface | 85 | 24 |
+| interface | 86 | 25 |
 | Go (the word) | 13 | 8 |
 | Go code fence | 12 | 1 |
 | Go stdlib | 9 | 5 |
@@ -234,7 +244,7 @@ Soft residue by token (130 lines):
 | race detector | 2 | 2 |
 | sync. | 1 | 1 |
 
-Soft residue by file (130 lines):
+Soft residue by file (131 lines):
 
 | File | Lines | Tokens |
 |---|---:|---:|
@@ -273,5 +283,6 @@ Soft residue by file (130 lines):
 | `rules/R2-self-validating-types.md` | 1 | 1 |
 | `rules/R7-test-placement.md` | 1 | 1 |
 | `scripts/ldd-scope_test.sh` | 1 | 1 |
+| `setup/golangci.yaml` | 1 | 1 |
 | `skills/linter-driven-development/SKILL.md` | 1 | 1 |
 <!-- residue:end -->
diff --git a/core/includes/scripts/ldd-lint-langs.sh b/core/includes/scripts/ldd-lint-langs.sh
index 4a7509b..ea3e885 100644
--- a/core/includes/scripts/ldd-lint-langs.sh
+++ b/core/includes/scripts/ldd-lint-langs.sh
@@ -21,9 +21,15 @@
 #                                   nothing. A named rule belongs to the linter:
 #                                   its limit, its counting and whether it is on
 #                                   are the repository's decision.
-#   lint_file_length_snippet <id> <max>  the linter setting that would hold the
-#                                   limit, or the .ldd-lint.yaml entry when no
-#                                   linter rule is known: text to propose
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
 
 lint_comment_style() {
   case "$1" in
@@ -112,8 +118,10 @@ lint_file_length_rule() {
       f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
         && printf 'revive file-length-limit in %s' "$f" ;;
     typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
       local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
-                     .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
       if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
         printf 'sonarjs/max-lines in %s' "$f"
       elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
@@ -126,12 +134,27 @@ lint_file_length_rule() {
   return 0
 }
 
-lint_file_length_snippet() {
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
   case "$1" in
-    go)                    printf "revive in .golangci.yaml: - name: file-length-limit, arguments: [{max: %s, skip-comments: true, skip-blank-lines: true}]" "$2" ;;
-    typescript|javascript) printf "the eslint config: 'sonarjs/max-lines': ['error', { maximum: %s }]" "$2" ;;
-    python)                printf "pyproject.toml: [tool.pylint.format] max-module-lines = %s (pylint counts every line, comments and blank lines too)" "$2" ;;
-    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: %s would state this limit" "$1" "$2" ;;
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
   esac
 }
 # ================== end linter table ==================
\ No newline at end of file
diff --git a/core/scripts/ldd-lint.sh b/core/scripts/ldd-lint.sh
index 90d76ae..5710d7f 100755
--- a/core/scripts/ldd-lint.sh
+++ b/core/scripts/ldd-lint.sh
@@ -162,6 +162,16 @@ trap 'rm -f "$SCOPE" "$INVENTORY"' EXIT
 list_candidates | by_language > "$SCOPE"
 if [[ -n "$FILES_LIST" ]]; then list_repo | by_language > "$INVENTORY"; else cp "$SCOPE" "$INVENTORY"; fi
 
+# dir_of <path> — the directory part of a relative path, "." for a file at
+# the root. A function, because bash 3.2 misreads a case pattern's ")" inside
+# a process substitution.
+dir_of() {
+  case "$1" in
+    */*) printf '%s\n' "${1%/*}" ;;
+    *)   printf '.\n' ;;
+  esac
+}
+
 # measured <path> — exit 0 when the file counts for this language: not under
 # an excluded directory, not a test, not generated. Every path the script
 # hands to find, head or awk starts with "./", and a directory is cut from a
@@ -193,7 +203,7 @@ run_file_length() { # <id> — every measured file of that language
     say "threshold: $id file length — set by $OVERRIDE_FILE ($max code lines)"
   else
     max="$DEFAULT_FILE_MAX_LINES"; src="profile default"
-    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; a setting to propose, never to add on your own: $(lint_file_length_snippet "$id" "$max")"
+    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; $(lint_file_length_proposal "$id")"
   fi
   while IFS=$'\t' read -r _ f; do
     measured "$f" || continue
@@ -217,7 +227,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
   awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$INVENTORY" | while IFS= read -r f; do
     [[ -n "$skip" ]] && printf '%s\n' "$f" | grep -qE -- "$skip" && continue
     measured "$f" || continue
-    case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+    dir_of "$f"
   done | LC_ALL=C sort | uniq -c | awk '{ n = $1; sub(/^[ \t]*[0-9]+[ \t]/, ""); print $0 "\t" n }' > "$counts"
   while IFS= read -r d; do
     n=$(awk -F'\t' -v d="$d" '$1 == d { print $2; exit }' "$counts")
@@ -228,8 +238,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
       finding "$d" "$n source files (warning at $warn, $src)"
     fi
   done < <(awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$SCOPE" | while IFS= read -r f; do
-             measured "$f" || continue
-             case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+             measured "$f" && dir_of "$f"
            done | LC_ALL=C sort -u)
   rm -f "$counts"
 }
diff --git a/core/scripts/ldd-lint_test.sh b/core/scripts/ldd-lint_test.sh
index 3b81d47..cce23a0 100644
--- a/core/scripts/ldd-lint_test.sh
+++ b/core/scripts/ldd-lint_test.sh
@@ -87,6 +87,8 @@ fill_dir() {
 
 {{include "scripts/ldd-fixture.sh"}}
 
+{{include "scripts/ldd-lint-langs.sh"}}
+
 # ========================= cases =========================
 run_row_cases() { # runs every case against the current row
 
@@ -146,7 +148,16 @@ finish
 begin "the plugin's default names a linter setting to propose, never to add"
 write_src "src/a$FX_EXT" 1
 run_lint file-length
-expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a setting to propose, never to add on your own: " && ok
+SETUP_DIR="$(dirname "$LINT")/../setup"
+if [[ -n "$FX_SETUP_FILE" ]]; then
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" \
+    && expect_has "a setting to propose, never to add on your own: " \
+    && expect_has "$FX_LENGTH_RULE, as the plugin's setup/$FX_SETUP_FILE sets it" \
+    && { grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && grep -q -- "$MAX_LINES" "$SETUP_DIR/$FX_SETUP_FILE" || bad "setup/$FX_SETUP_FILE does not set $FX_LENGTH_RULE at $MAX_LINES"; } \
+    && grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && ok
+else
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a .ldd-lint.yaml entry file_max_lines" && ok
+fi
 finish
 
 begin "a file-length rule in the linter config hands file length to the linter"
@@ -178,6 +189,39 @@ run_lint file-length
 expect_exit 0 && expect_not "held by " && expect_has "src/over$FX_EXT: $((MAX_LINES + 1)) code lines" && ok
 finish
 
+begin "the recommended config enables every rule the routing table routes to a design rule"
+if [[ -z "$FX_ROUTED_FILE" ]]; then skip "this plugin's routing table names no linter rule"; finish
+else
+  table=$(grep -l '^| Linter failure | Route |' "$(dirname "$LINT")"/../skills/refactoring/*.md | head -1)
+  missing=""; checked=0
+  while IFS= read -r id; do
+    case " $FX_ROUTED_SKIP " in *" $id "*) continue ;; esac
+    checked=$((checked + 1))
+    case "$id" in
+      *'*') re="(^|[^A-Za-z0-9/@-])${id%\*}" ;;
+      *)    re="(^|[^A-Za-z0-9/@-])${id}([^A-Za-z0-9/-]|\$)" ;;
+    esac
+    grep -qE -- "$re" "$(dirname "$LINT")/../setup/$FX_ROUTED_FILE" || missing="$missing $id"
+  done < <(awk -F'|' '
+      /^\| Linter failure \| Route \|/ { t = 1; next }
+      t && /^\|---/ { next }
+      t && /^\|/ { if ($3 ~ /rules\/R/) { c = $2; while (match(c, /`[^`]+`/)) { print substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) } } next }
+      t { t = 0 }' "$table" | grep -E -- "$FX_RULE_ID_RE" | LC_ALL=C sort -u)
+  { [[ -n "$table" ]] && (( checked > 0 )) || bad "no routed rule id found in the routing table"; } \
+    && { [[ -z "$missing" ]] || bad "setup/$FX_ROUTED_FILE lacks:$missing"; } && [[ -z "$missing" ]] && ok
+  finish
+fi
+
+begin "the recommended fragment, kept as its own file and imported, hands file length to the linter"
+if [[ -z "$FX_ADOPTED_CONFIG" ]]; then skip "this language's setup is copied into the linter's own config"; finish
+else
+  cp "$(dirname "$LINT")/../setup/$FX_ADOPTED_CONFIG" "$REPO/$FX_ADOPTED_CONFIG"
+  write_src "src/over$FX_EXT" $((MAX_LINES + 50))
+  run_lint file-length
+  expect_exit 0 && expect_has "held by " && expect_has "in $FX_ADOPTED_CONFIG" && expect_no_finding && ok
+  finish
+fi
+
 begin ".ldd-lint.yaml sets the limit when the linter holds none"
 printf 'file_max_lines: 100  # this repository\n' > "$REPO/.ldd-lint.yaml"
 write_src "src/a$FX_EXT" 101
@@ -316,6 +360,18 @@ for opt in --root --files --glob --test-re; do
   finish
 done
 
+# --- the recommended configs under setup/, checked by their own linters when
+# the machine has them ---
+SETUP_DIR="$(dirname "$LINT")/../setup"
+
+while IFS=$'\t' read -r setup_file setup_tool; do
+  begin "setup/$setup_file passes its own linter's check"
+  if ! command -v "$setup_tool" >/dev/null 2>&1; then skip "$setup_tool is not on PATH"; finish; continue; fi
+  OUT=$(lint_setup_check "$setup_file" "$SETUP_DIR" "$REPO" 2>&1); CODE=$?; ERR=""
+  expect_exit 0 && ok
+  finish
+done < <(lint_setup_files)
+
 # ========================= summary =========================
 echo
 echo "ldd-lint_test: $pass passed, $failed failed, $skipped skipped"
diff --git a/core/setup/eslint.config.ldd.mjs b/core/setup/eslint.config.ldd.mjs
new file mode 100644
index 0000000..d679c76
--- /dev/null
+++ b/core/setup/eslint.config.ldd.mjs
@@ -0,0 +1,115 @@
+// Recommended ESLint flat-config fragment of the linter-driven-development
+// plugins: every rule the plugin's routing table routes to one of the twelve
+// design rules, at the limits the rules name. Each rule line says which rule its
+// failures feed. The plugin never writes this file into a repository: the
+// repository's owners copy it, or the parts they want, beside eslint.config.js
+// and spread it before their own entries. Later entries win, so every limit the
+// repository's config already sets stays the repository's:
+//
+//   import ldd from './eslint.config.ldd.mjs'
+//   export default [...ldd, ...yourConfig]
+//
+// residue-exempt: an ESLint configuration names its plugins and rules on purpose.
+// It needs eslint-plugin-sonarjs, eslint-plugin-react, eslint-plugin-react-hooks,
+// eslint-plugin-promise, eslint-plugin-import and typescript-eslint; a repository
+// that does not use one of them leaves its rules out. The @typescript-eslint rules
+// below need type information: the repository's config sets typescript-eslint's
+// parser with parserOptions.projectService for these files, or ESLint stops with
+// an error. Limits a repository already sets stay the repository's: the linter is
+// the authority for every threshold it holds. Rules this file leaves out (style,
+// imports, formatting) are the repository's own choice, and so is
+// no-restricted-syntax on import.meta.env outside the config module (R8): the
+// config module's path is the repository's.
+//
+// Adopt it on an existing codebase with ESLint's bulk suppressions: run
+// `npx eslint --suppress-all` once to record today's violations, so only new ones
+// fail; `npx eslint --prune-suppressions` drops the entries that are fixed.
+
+import importPlugin from 'eslint-plugin-import'
+import promise from 'eslint-plugin-promise'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import sonarjs from 'eslint-plugin-sonarjs'
+import tseslint from 'typescript-eslint'
+
+export default [
+  {
+    files: ['**/*.{ts,tsx}'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+      import: importPlugin,
+      promise,
+      react,
+      'react-hooks': reactHooks,
+      sonarjs,
+    },
+    rules: {
+      // R3 storifying
+      'sonarjs/cognitive-complexity': ['error', 15],
+      'sonarjs/cyclomatic-complexity': ['error', { threshold: 10 }],
+      'sonarjs/expression-complexity': ['error', { max: 5 }],
+      // R3's limits: more than 50 lines or more than 2 nesting levels
+      'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],
+      'sonarjs/nested-control-flow': ['error', { maximumNestingLevel: 2 }],
+      'sonarjs/no-nested-conditional': 'error',
+      'sonarjs/no-nested-functions': 'error',
+      'sonarjs/elseif-without-else': 'error',
+      'react/no-unstable-nested-components': 'error',
+      // R1 primitive obsession
+      'max-params': ['error', 4],
+      'sonarjs/no-duplicate-string': ['error', { threshold: 3 }],
+      'sonarjs/max-union-size': ['error', { threshold: 4 }],
+      'sonarjs/no-identical-functions': 'error',
+      'react/no-array-index-key': 'error',
+      'no-magic-numbers': ['error', {
+        ignore: [-1, 0, 1, 2],
+        ignoreArrayIndexes: true,
+        ignoreDefaultValues: true,
+        ignoreClassFieldInitialValues: true,
+        detectObjects: false,
+      }],
+      // R2 self-validating types: parse at the boundary
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'error',
+      '@typescript-eslint/no-unsafe-assignment': 'error',
+      '@typescript-eslint/no-unsafe-call': 'error',
+      '@typescript-eslint/no-unsafe-member-access': 'error',
+      '@typescript-eslint/no-unsafe-return': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'error',
+      // R5 vertical slice: one juicy module per file; counts code lines only
+      'sonarjs/max-lines': ['error', { maximum: {{.FileMaxLines}} }],
+      'react/no-multi-comp': ['error', { ignoreStateless: false }],
+      // R8 no globals
+      'import/no-mutable-exports': 'error',
+      // R10 concurrency safety
+      'react-hooks/exhaustive-deps': 'error',
+      'react-hooks/set-state-in-effect': 'error',
+      '@typescript-eslint/no-floating-promises': 'error',
+      '@typescript-eslint/no-misused-promises': 'error',
+      'promise/catch-or-return': 'error',
+      // R11 conditional dispatch
+      '@typescript-eslint/switch-exhaustiveness-check': 'error',
+      'sonarjs/no-nested-switch': 'error',
+      'sonarjs/max-switch-cases': 'error',
+      'sonarjs/no-small-switch': 'error',
+      // R12 mutation discipline
+      'no-param-reassign': ['error', { props: true }],
+      'sonarjs/prefer-read-only-props': 'error',
+      'react/no-direct-mutation-state': 'error',
+    },
+  },
+  {
+    // Tests are long and repeat literals by design.
+    files: ['**/*.test.{ts,tsx}', '**/*.spec.{ts,tsx}'],
+    rules: {
+      'sonarjs/max-lines-per-function': 'off',
+      'sonarjs/no-duplicate-string': 'off',
+      'sonarjs/no-nested-functions': 'off',
+      'max-params': 'off',
+      'no-magic-numbers': 'off',
+      'react/no-multi-comp': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+]
diff --git a/core/setup/golangci.yaml b/core/setup/golangci.yaml
new file mode 100644
index 0000000..be5a0ac
--- /dev/null
+++ b/core/setup/golangci.yaml
@@ -0,0 +1,86 @@
+# Recommended golangci-lint v2 configuration of the linter-driven-development
+# plugins: every linter rule the plugin's routing table routes to one of the
+# twelve design rules, at the limits the rules name. Each linter line says which
+# rule its failures feed. The plugin never writes this file into a repository:
+# the repository's owners copy it, or the parts they want, into .golangci.yaml.
+# residue-exempt: a golangci-lint configuration names its linters on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# naming, formatting) are the repository's own choice.
+#
+# Adopt it on an existing codebase with the ratchet below: only issues in code
+# changed since the merge base with main fail, so old code is not a wall of
+# findings on day one. CI needs main in the clone for it (fetch-depth: 0 in
+# GitHub Actions). Remove the ratchet once the old findings are gone.
+# gocyclo stands for the routing table's "gocyclo / cyclop": enable one of the two.
+
+version: "2"
+
+issues:
+  new-from-merge-base: main
+
+linters:
+  # The standard set (errcheck, govet, ineffassign, staticcheck, unused) stays on;
+  # the linters below are added to it.
+  default: standard
+  enable:
+    - gocyclo           # R3 storifying: cyclomatic complexity
+    - gocognit          # R3 storifying: cognitive complexity
+    - funlen            # R3 storifying: function length
+    - nestif            # R3 storifying: nesting depth
+    - maintidx          # R3 storifying, R1 types: maintainability index
+    - dupl              # R1 types: duplicated logic; a duplicated switch is R11
+    - exhaustive        # R11 conditional dispatch: missing enum cases
+    - gochecknoglobals  # R8 no globals
+    - gochecknoinits    # R8 no globals
+    - ireturn           # R6 test-only interfaces: a constructor that returns an interface
+    - govet             # R10 concurrency: copylocks
+    - revive            # R1 types, R5 vertical slice: the rules below
+    - errcheck          # mechanical: an error that is not handled
+    - wrapcheck         # mechanical: an error without the context of its layer
+    - goconst           # mechanical; an enum-shaped string is R1's "Name enum strings"
+  settings:
+    gocyclo:
+      min-complexity: 10
+    gocognit:
+      min-complexity: 15
+    funlen:
+      lines: 50
+      statements: 40
+    nestif:
+      min-complexity: 2
+    maintidx:
+      under: 20
+    dupl:
+      threshold: 100
+    exhaustive:
+      # A default branch does not count as handling a case: every new case is
+      # handled where the switch is.
+      default-signifies-exhaustive: false
+    govet:
+      enable:
+        - copylocks
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    revive:
+      rules:
+        - name: argument-limit          # R1: more than 4 parameters wants a parameter object
+          arguments: [4]
+        - name: function-result-limit   # R1: more than 3 results wants a named result type
+          arguments: [3]
+        - name: file-length-limit       # R5: one juicy type per file; counts code lines only
+          arguments: [{max: {{.FileMaxLines}}, skip-comments: true, skip-blank-lines: true}]
+        - name: early-return            # mechanical: invert the condition and return early
+  exclusions:
+    rules:
+      # Tests are long and repeat literals by design.
+      - path: _test\.go
+        linters:
+          - funlen
+          - gocognit
+          - gocyclo
+          - maintidx
+          - dupl
+          - goconst
diff --git a/core/setup/ruff.toml b/core/setup/ruff.toml
new file mode 100644
index 0000000..bca37e5
--- /dev/null
+++ b/core/setup/ruff.toml
@@ -0,0 +1,58 @@
+# Recommended ruff configuration of the linter-driven-development plugins:
+# every rule the plugin's routing table routes to one of the twelve design
+# rules, at the limits the rules name. Each rule says which rule its failures
+# feed. The plugin never writes this file into a repository: the repository's
+# owners copy it, or the parts they want, into ruff.toml, or into
+# pyproject.toml with each table name prefixed by "tool.ruff." ([lint] becomes
+# [tool.ruff.lint]).
+# residue-exempt: a ruff configuration names its rule codes on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# docstrings, imports) are the repository's own choice. ruff has no file-length
+# rule: the plugin's gap linter, scripts/ldd-lint.sh file-length, holds that
+# limit at {{.FileMaxLines}} code lines.
+#
+# Adopt it on an existing codebase one change at a time: run ruff on the files
+# changed since the merge base with main, so old code is not a wall of
+# findings on day one:
+#   git diff -z --name-only --diff-filter=d "$(git merge-base HEAD main)" -- '*.py' \
+#     | xargs -0 sh -c '[ "$#" -eq 0 ] || ruff check "$@"' sh
+# The sh guard keeps an empty change list from checking the whole repository,
+# and -z with -0 keeps a path with spaces whole.
+
+[lint]
+# PLR1702 (nested blocks) is a preview rule. Preview mode also turns on preview
+# behavior of the stable rules a repository already selects; a repository that
+# does not want that drops these two lines and PLR1702.
+preview = true
+explicit-preview-rules = true
+extend-select = [
+  "C901",     # R3 storifying: complexity
+  "PLR0911",  # R3 storifying: too many returns
+  "PLR0912",  # R3 storifying: too many branches
+  "PLR0915",  # R3 storifying: too many statements
+  "PLR1702",  # R3 storifying: nesting
+  "PLR0913",  # R1 types: too many arguments wants a parameter object
+  "PLR2004",  # R1 types: a magic value; an enum-shaped string is "Name enum strings"
+  "FBT001",   # R11 conditional dispatch: a boolean positional parameter
+  "FBT002",   # R11 conditional dispatch: a boolean default parameter
+  "PLW0603",  # R8 no globals: a global statement
+  "B006",     # R12 mutation discipline: a mutable default argument
+  "B008",     # R12 mutation discipline: a call in a default argument
+]
+
+[lint.mccabe]
+max-complexity = 8
+
+[lint.pylint]
+max-args = 4          # self and cls are not counted
+max-branches = 12
+max-returns = 6
+max-statements = 50
+max-nested-blocks = 2  # R3: more than 2 nesting levels
+
+[lint.per-file-ignores]
+# Tests repeat literals and take many fixtures by design.
+"**/test_*.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
+"**/*_test.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
diff --git a/docs/quick-start.md b/docs/quick-start.md
index 3b60ecf..9d92c40 100644
--- a/docs/quick-start.md
+++ b/docs/quick-start.md
@@ -25,8 +25,11 @@ they share it.
 /plugin install go-linter-driven-development@ai-coding-rules
 ```
 
-No configuration. The plugin finds your test and lint commands in the Taskfile,
-Makefile, README or CLAUDE.md. The first time the workflow starts, Claude asks for
+No configuration to run. The plugin finds your test and lint commands in the
+Taskfile, Makefile, README or CLAUDE.md. The plugin's `setup/` directory holds a
+recommended linter configuration for Go, Python and TypeScript; copying it, or the
+parts you want, makes the design triggers fire. The plugin never writes it into
+your repository. The first time the workflow starts, Claude asks for
 permission to use the skill. Choose "Yes, and don't ask again for this directory".
 
 ## 1. A feature or a bug fix, from zero
diff --git a/go-linter-driven-development/CHANGELOG.md b/go-linter-driven-development/CHANGELOG.md
index 36bff47..ef2e41a 100644
--- a/go-linter-driven-development/CHANGELOG.md
+++ b/go-linter-driven-development/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -33,6 +42,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/go-linter-driven-development/README.md b/go-linter-driven-development/README.md
index 5c15ab5..b7f0d41 100644
--- a/go-linter-driven-development/README.md
+++ b/go-linter-driven-development/README.md
@@ -209,7 +209,9 @@ Should show: `go-linter-driven-development (enabled)`
 
 The scenario guide — the easiest start first, then code you already wrote, a plan you already have, and running the plugin from a subagent — is [docs/quick-start.md](https://github.com/buzzdan/ai-coding-rules/blob/main/docs/quick-start.md) in the main repository.
 
-**Zero configuration required.** The plugin discovers your project's test and lint commands from `README.md`, `CLAUDE.md`, `Makefile`, or `Taskfile.yaml`. Just install and go.
+**Zero configuration to run.** The plugin discovers your project's test and lint commands from `README.md`, `CLAUDE.md`, `Makefile`, or `Taskfile.yaml`. Just install and go.
+
+**The recommended setup makes the design triggers fire.** `setup/golangci.yaml` in the plugin directory enables every linter the routing table routes to a design rule, at the limits the rules name, with a ratchet so only new code fails at first. The plugin never writes it into your repository: copy it, or the parts you want, into `.golangci.yaml`. Limits your configuration already sets stay yours.
 
 ### The Easiest Way: Just Talk to It
 
diff --git a/go-linter-driven-development/scripts/ldd-detect_test.sh b/go-linter-driven-development/scripts/ldd-detect_test.sh
index a1822b0..7d7a85e 100644
--- a/go-linter-driven-development/scripts/ldd-detect_test.sh
+++ b/go-linter-driven-development/scripts/ldd-detect_test.sh
@@ -141,6 +141,18 @@ questions_in_rules() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -156,6 +168,13 @@ FX_NATIVE="go"
 
 use_row() {
   FX_LINTER_CONFIG='.golangci.yaml'
+  FX_SETUP_FILE='golangci.yaml'
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='golangci.yaml'
+  FX_RULE_ID_RE='^[a-z][a-z0-9-]*$'
+  # cyclop is the alternative to gocyclo; package-size is the gap linter's
+  FX_ROUTED_SKIP='cyclop package-size'
+  FX_LENGTH_RULE='file-length-limit'
   FX_LINTER_COMMENT='#'
   FX_EXT='.go'
   FX_LINE_COMMENT='// note'
diff --git a/go-linter-driven-development/scripts/ldd-lint.sh b/go-linter-driven-development/scripts/ldd-lint.sh
index 3423749..8658fc0 100755
--- a/go-linter-driven-development/scripts/ldd-lint.sh
+++ b/go-linter-driven-development/scripts/ldd-lint.sh
@@ -222,9 +222,15 @@ lang_is_test() {
 #                                   nothing. A named rule belongs to the linter:
 #                                   its limit, its counting and whether it is on
 #                                   are the repository's decision.
-#   lint_file_length_snippet <id> <max>  the linter setting that would hold the
-#                                   limit, or the .ldd-lint.yaml entry when no
-#                                   linter rule is known: text to propose
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
 
 lint_comment_style() {
   case "$1" in
@@ -313,8 +319,10 @@ lint_file_length_rule() {
       f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
         && printf 'revive file-length-limit in %s' "$f" ;;
     typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
       local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
-                     .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
       if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
         printf 'sonarjs/max-lines in %s' "$f"
       elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
@@ -327,12 +335,27 @@ lint_file_length_rule() {
   return 0
 }
 
-lint_file_length_snippet() {
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
   case "$1" in
-    go)                    printf "revive in .golangci.yaml: - name: file-length-limit, arguments: [{max: %s, skip-comments: true, skip-blank-lines: true}]" "$2" ;;
-    typescript|javascript) printf "the eslint config: 'sonarjs/max-lines': ['error', { maximum: %s }]" "$2" ;;
-    python)                printf "pyproject.toml: [tool.pylint.format] max-module-lines = %s (pylint counts every line, comments and blank lines too)" "$2" ;;
-    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: %s would state this limit" "$1" "$2" ;;
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
   esac
 }
 # ================== end linter table ==================
@@ -404,6 +427,16 @@ trap 'rm -f "$SCOPE" "$INVENTORY"' EXIT
 list_candidates | by_language > "$SCOPE"
 if [[ -n "$FILES_LIST" ]]; then list_repo | by_language > "$INVENTORY"; else cp "$SCOPE" "$INVENTORY"; fi
 
+# dir_of <path> — the directory part of a relative path, "." for a file at
+# the root. A function, because bash 3.2 misreads a case pattern's ")" inside
+# a process substitution.
+dir_of() {
+  case "$1" in
+    */*) printf '%s\n' "${1%/*}" ;;
+    *)   printf '.\n' ;;
+  esac
+}
+
 # measured <path> — exit 0 when the file counts for this language: not under
 # an excluded directory, not a test, not generated. Every path the script
 # hands to find, head or awk starts with "./", and a directory is cut from a
@@ -435,7 +468,7 @@ run_file_length() { # <id> — every measured file of that language
     say "threshold: $id file length — set by $OVERRIDE_FILE ($max code lines)"
   else
     max="$DEFAULT_FILE_MAX_LINES"; src="profile default"
-    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; a setting to propose, never to add on your own: $(lint_file_length_snippet "$id" "$max")"
+    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; $(lint_file_length_proposal "$id")"
   fi
   while IFS=$'\t' read -r _ f; do
     measured "$f" || continue
@@ -459,7 +492,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
   awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$INVENTORY" | while IFS= read -r f; do
     [[ -n "$skip" ]] && printf '%s\n' "$f" | grep -qE -- "$skip" && continue
     measured "$f" || continue
-    case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+    dir_of "$f"
   done | LC_ALL=C sort | uniq -c | awk '{ n = $1; sub(/^[ \t]*[0-9]+[ \t]/, ""); print $0 "\t" n }' > "$counts"
   while IFS= read -r d; do
     n=$(awk -F'\t' -v d="$d" '$1 == d { print $2; exit }' "$counts")
@@ -470,8 +503,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
       finding "$d" "$n source files (warning at $warn, $src)"
     fi
   done < <(awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$SCOPE" | while IFS= read -r f; do
-             measured "$f" || continue
-             case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+             measured "$f" && dir_of "$f"
            done | LC_ALL=C sort -u)
   rm -f "$counts"
 }
diff --git a/go-linter-driven-development/scripts/ldd-lint_test.sh b/go-linter-driven-development/scripts/ldd-lint_test.sh
index 7638faf..eb3a00e 100644
--- a/go-linter-driven-development/scripts/ldd-lint_test.sh
+++ b/go-linter-driven-development/scripts/ldd-lint_test.sh
@@ -105,6 +105,18 @@ fill_dir() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -120,6 +132,13 @@ FX_NATIVE="go"
 
 use_row() {
   FX_LINTER_CONFIG='.golangci.yaml'
+  FX_SETUP_FILE='golangci.yaml'
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='golangci.yaml'
+  FX_RULE_ID_RE='^[a-z][a-z0-9-]*$'
+  # cyclop is the alternative to gocyclo; package-size is the gap linter's
+  FX_ROUTED_SKIP='cyclop package-size'
+  FX_LENGTH_RULE='file-length-limit'
   FX_LINTER_COMMENT='#'
   FX_EXT='.go'
   FX_LINE_COMMENT='// note'
@@ -180,6 +199,167 @@ fx_write_linter_config_other() {
   printf 'version: "2"\nlinters:\n  settings:\n    revive:\n      rules:\n        - name: argument-limit\n          arguments: [4]\n' > "$REPO/.golangci.yaml"
 }
 
+# ==================== linter table ====================
+# What the gap linter needs to know per language id: how a comment is written,
+# which source files a directory count leaves out, and whether the
+# repository's own linter holds the file-length limit. The same table is
+# rendered into every plugin, so two plugins measure one file the same way.
+# residue-exempt: the table names every language's linter and config file on
+# purpose, the same in every rendering.
+#
+#   lint_comment_style <id>         c (// and /* */), d (also /+ +/) or hash (#)
+#   lint_strip_comments <style> <file>  the file with every comment removed and
+#                                   string literals kept, one output line per
+#                                   input line: a comment-only line prints empty.
+#                                   Styles: c, d, hash (# and triple-quoted
+#                                   strings), ini (# and a leading ;)
+#   lint_package_skip_re <id>       ERE over a relative path: source files a
+#                                   directory count leaves out (an index module,
+#                                   a package marker, generated stubs); "" for none
+#   lint_file_length_rule <id>      "<rule> in <config file>" when a linter config
+#                                   at the repository root names a file-length
+#                                   rule outside a comment, else
+#                                   nothing. A named rule belongs to the linter:
+#                                   its limit, its counting and whether it is on
+#                                   are the repository's decision.
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
+
+lint_comment_style() {
+  case "$1" in
+    python|ruby|shell) printf 'hash' ;;
+    d)                 printf 'd' ;;
+    *)                 printf 'c' ;;
+  esac
+}
+
+lint_package_skip_re() {
+  case "$1" in
+    go)                    printf '%s' '(_gen|\.pb)\.go$' ;;
+    python)                printf '%s' '(^|/)(__init__|conftest)\.py$|_pb2(_grpc)?\.py$' ;;
+    typescript|javascript) printf '%s' '(^|/)index\.[cm]?[jt]sx?$|\.stories\.[cm]?[jt]sx?$' ;;
+  esac
+  return 0
+}
+
+# LINT_STRIP_AWK walks each line one character at a time. A quote opens a
+# string that a comment marker cannot end; single and double quotes close at
+# the end of the line, a backtick string (c and d) and a triple-quoted string
+# (hash) run on. A block comment may open after code and run on. The awk uses
+# substr and string compares only, so mawk, gawk and BSD awk read it alike.
+LINT_STRIP_AWK='
+BEGIN { bq = sprintf("%c", 96); sq = sprintf("%c", 39); dq = "\"" }
+{
+  line = $0; out = ""; n = length(line); i = 1
+  if (q == dq || q == sq) q = ""
+  while (i <= n) {
+    if (inblock) {
+      if (substr(line, i, length(closer)) == closer) { inblock = 0; i += length(closer); out = out " "; continue }
+      i++; continue
+    }
+    ch = substr(line, i, 1)
+    if (q != "") {
+      if (ch == "\\" && (q == dq || q == sq)) { out = out substr(line, i, 2); i += 2; continue }
+      if (substr(line, i, length(q)) == q) { out = out q; i += length(q); q = ""; continue }
+      out = out ch; i++; continue
+    }
+    if (style == "hash" || style == "ini") {
+      if (ch == "#") break
+      if (style == "ini" && ch == ";" && out ~ /^[ \t]*$/) break
+      three = substr(line, i, 3)
+      if (style == "hash" && (three == dq dq dq || three == sq sq sq)) { q = three; out = out three; i += 3; continue }
+    } else {
+      two = substr(line, i, 2)
+      if (two == "//") break
+      if (two == "/*" || (style == "d" && two == "/+")) { inblock = 1; closer = (two == "/+") ? "+/" : "*/"; out = out " "; i += 2; continue }
+      if (ch == bq) { q = bq; out = out ch; i++; continue }
+    }
+    if (ch == dq || ch == sq) { q = ch; out = out ch; i++; continue }
+    out = out ch; i++
+  }
+  print out
+}
+'
+
+lint_strip_comments() { # <style> <file>
+  awk -v style="$1" "$LINT_STRIP_AWK" "$2"
+}
+
+# _lint_config_style <config file> — how that config format writes a comment
+_lint_config_style() {
+  case "$1" in
+    *.yaml|*.yml|*.toml) printf 'hash' ;;
+    *.cfg|*.ini|.pylintrc|pylintrc) printf 'ini' ;;
+    *) printf 'c' ;;
+  esac
+}
+
+# _lint_names <ERE> <file>... — print the first file whose text outside its
+# comments matches the pattern
+_lint_names() {
+  local re="$1" f; shift
+  for f in "$@"; do
+    [[ -f "$f" ]] || continue
+    lint_strip_comments "$(_lint_config_style "$f")" "./$f" 2>/dev/null | grep -qE -- "$re" && { printf '%s' "$f"; return 0; }
+  done
+  return 1
+}
+
+lint_file_length_rule() {
+  local f
+  case "$1" in
+    go)
+      f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
+        && printf 'revive file-length-limit in %s' "$f" ;;
+    typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
+      local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+      if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'sonarjs/max-lines in %s' "$f"
+      elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'max-lines in %s' "$f"
+      fi ;;
+    python)
+      f=$(_lint_names '^[[:space:]]*max-module-lines[[:space:]]*=' pyproject.toml .pylintrc pylintrc setup.cfg tox.ini) \
+        && printf 'pylint max-module-lines in %s' "$f" ;;
+  esac
+  return 0
+}
+
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
+  case "$1" in
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
+  esac
+}
+# ================== end linter table ==================
+
 # ========================= cases =========================
 run_row_cases() { # runs every case against the current row
 
@@ -239,7 +419,16 @@ finish
 begin "the plugin's default names a linter setting to propose, never to add"
 write_src "src/a$FX_EXT" 1
 run_lint file-length
-expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a setting to propose, never to add on your own: " && ok
+SETUP_DIR="$(dirname "$LINT")/../setup"
+if [[ -n "$FX_SETUP_FILE" ]]; then
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" \
+    && expect_has "a setting to propose, never to add on your own: " \
+    && expect_has "$FX_LENGTH_RULE, as the plugin's setup/$FX_SETUP_FILE sets it" \
+    && { grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && grep -q -- "$MAX_LINES" "$SETUP_DIR/$FX_SETUP_FILE" || bad "setup/$FX_SETUP_FILE does not set $FX_LENGTH_RULE at $MAX_LINES"; } \
+    && grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && ok
+else
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a .ldd-lint.yaml entry file_max_lines" && ok
+fi
 finish
 
 begin "a file-length rule in the linter config hands file length to the linter"
@@ -271,6 +460,39 @@ run_lint file-length
 expect_exit 0 && expect_not "held by " && expect_has "src/over$FX_EXT: $((MAX_LINES + 1)) code lines" && ok
 finish
 
+begin "the recommended config enables every rule the routing table routes to a design rule"
+if [[ -z "$FX_ROUTED_FILE" ]]; then skip "this plugin's routing table names no linter rule"; finish
+else
+  table=$(grep -l '^| Linter failure | Route |' "$(dirname "$LINT")"/../skills/refactoring/*.md | head -1)
+  missing=""; checked=0
+  while IFS= read -r id; do
+    case " $FX_ROUTED_SKIP " in *" $id "*) continue ;; esac
+    checked=$((checked + 1))
+    case "$id" in
+      *'*') re="(^|[^A-Za-z0-9/@-])${id%\*}" ;;
+      *)    re="(^|[^A-Za-z0-9/@-])${id}([^A-Za-z0-9/-]|\$)" ;;
+    esac
+    grep -qE -- "$re" "$(dirname "$LINT")/../setup/$FX_ROUTED_FILE" || missing="$missing $id"
+  done < <(awk -F'|' '
+      /^\| Linter failure \| Route \|/ { t = 1; next }
+      t && /^\|---/ { next }
+      t && /^\|/ { if ($3 ~ /rules\/R/) { c = $2; while (match(c, /`[^`]+`/)) { print substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) } } next }
+      t { t = 0 }' "$table" | grep -E -- "$FX_RULE_ID_RE" | LC_ALL=C sort -u)
+  { [[ -n "$table" ]] && (( checked > 0 )) || bad "no routed rule id found in the routing table"; } \
+    && { [[ -z "$missing" ]] || bad "setup/$FX_ROUTED_FILE lacks:$missing"; } && [[ -z "$missing" ]] && ok
+  finish
+fi
+
+begin "the recommended fragment, kept as its own file and imported, hands file length to the linter"
+if [[ -z "$FX_ADOPTED_CONFIG" ]]; then skip "this language's setup is copied into the linter's own config"; finish
+else
+  cp "$(dirname "$LINT")/../setup/$FX_ADOPTED_CONFIG" "$REPO/$FX_ADOPTED_CONFIG"
+  write_src "src/over$FX_EXT" $((MAX_LINES + 50))
+  run_lint file-length
+  expect_exit 0 && expect_has "held by " && expect_has "in $FX_ADOPTED_CONFIG" && expect_no_finding && ok
+  finish
+fi
+
 begin ".ldd-lint.yaml sets the limit when the linter holds none"
 printf 'file_max_lines: 100  # this repository\n' > "$REPO/.ldd-lint.yaml"
 write_src "src/a$FX_EXT" 101
@@ -409,6 +631,18 @@ for opt in --root --files --glob --test-re; do
   finish
 done
 
+# --- the recommended configs under setup/, checked by their own linters when
+# the machine has them ---
+SETUP_DIR="$(dirname "$LINT")/../setup"
+
+while IFS=$'\t' read -r setup_file setup_tool; do
+  begin "setup/$setup_file passes its own linter's check"
+  if ! command -v "$setup_tool" >/dev/null 2>&1; then skip "$setup_tool is not on PATH"; finish; continue; fi
+  OUT=$(lint_setup_check "$setup_file" "$SETUP_DIR" "$REPO" 2>&1); CODE=$?; ERR=""
+  expect_exit 0 && ok
+  finish
+done < <(lint_setup_files)
+
 # ========================= summary =========================
 echo
 echo "ldd-lint_test: $pass passed, $failed failed, $skipped skipped"
diff --git a/go-linter-driven-development/scripts/ldd-scope_test.sh b/go-linter-driven-development/scripts/ldd-scope_test.sh
index 9d7af0c..fe5d9fc 100755
--- a/go-linter-driven-development/scripts/ldd-scope_test.sh
+++ b/go-linter-driven-development/scripts/ldd-scope_test.sh
@@ -117,6 +117,18 @@ mk_repo() { fx_write_marker "$REPO" fixture; fx_write_code; mk_docs; }
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -132,6 +144,13 @@ FX_NATIVE="go"
 
 use_row() {
   FX_LINTER_CONFIG='.golangci.yaml'
+  FX_SETUP_FILE='golangci.yaml'
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='golangci.yaml'
+  FX_RULE_ID_RE='^[a-z][a-z0-9-]*$'
+  # cyclop is the alternative to gocyclo; package-size is the gap linter's
+  FX_ROUTED_SKIP='cyclop package-size'
+  FX_LENGTH_RULE='file-length-limit'
   FX_LINTER_COMMENT='#'
   FX_EXT='.go'
   FX_LINE_COMMENT='// note'
diff --git a/go-linter-driven-development/setup/eslint.config.ldd.mjs b/go-linter-driven-development/setup/eslint.config.ldd.mjs
new file mode 100644
index 0000000..85da438
--- /dev/null
+++ b/go-linter-driven-development/setup/eslint.config.ldd.mjs
@@ -0,0 +1,115 @@
+// Recommended ESLint flat-config fragment of the linter-driven-development
+// plugins: every rule the plugin's routing table routes to one of the twelve
+// design rules, at the limits the rules name. Each rule line says which rule its
+// failures feed. The plugin never writes this file into a repository: the
+// repository's owners copy it, or the parts they want, beside eslint.config.js
+// and spread it before their own entries. Later entries win, so every limit the
+// repository's config already sets stays the repository's:
+//
+//   import ldd from './eslint.config.ldd.mjs'
+//   export default [...ldd, ...yourConfig]
+//
+// residue-exempt: an ESLint configuration names its plugins and rules on purpose.
+// It needs eslint-plugin-sonarjs, eslint-plugin-react, eslint-plugin-react-hooks,
+// eslint-plugin-promise, eslint-plugin-import and typescript-eslint; a repository
+// that does not use one of them leaves its rules out. The @typescript-eslint rules
+// below need type information: the repository's config sets typescript-eslint's
+// parser with parserOptions.projectService for these files, or ESLint stops with
+// an error. Limits a repository already sets stay the repository's: the linter is
+// the authority for every threshold it holds. Rules this file leaves out (style,
+// imports, formatting) are the repository's own choice, and so is
+// no-restricted-syntax on import.meta.env outside the config module (R8): the
+// config module's path is the repository's.
+//
+// Adopt it on an existing codebase with ESLint's bulk suppressions: run
+// `npx eslint --suppress-all` once to record today's violations, so only new ones
+// fail; `npx eslint --prune-suppressions` drops the entries that are fixed.
+
+import importPlugin from 'eslint-plugin-import'
+import promise from 'eslint-plugin-promise'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import sonarjs from 'eslint-plugin-sonarjs'
+import tseslint from 'typescript-eslint'
+
+export default [
+  {
+    files: ['**/*.{ts,tsx}'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+      import: importPlugin,
+      promise,
+      react,
+      'react-hooks': reactHooks,
+      sonarjs,
+    },
+    rules: {
+      // R3 storifying
+      'sonarjs/cognitive-complexity': ['error', 15],
+      'sonarjs/cyclomatic-complexity': ['error', { threshold: 10 }],
+      'sonarjs/expression-complexity': ['error', { max: 5 }],
+      // R3's limits: more than 50 lines or more than 2 nesting levels
+      'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],
+      'sonarjs/nested-control-flow': ['error', { maximumNestingLevel: 2 }],
+      'sonarjs/no-nested-conditional': 'error',
+      'sonarjs/no-nested-functions': 'error',
+      'sonarjs/elseif-without-else': 'error',
+      'react/no-unstable-nested-components': 'error',
+      // R1 primitive obsession
+      'max-params': ['error', 4],
+      'sonarjs/no-duplicate-string': ['error', { threshold: 3 }],
+      'sonarjs/max-union-size': ['error', { threshold: 4 }],
+      'sonarjs/no-identical-functions': 'error',
+      'react/no-array-index-key': 'error',
+      'no-magic-numbers': ['error', {
+        ignore: [-1, 0, 1, 2],
+        ignoreArrayIndexes: true,
+        ignoreDefaultValues: true,
+        ignoreClassFieldInitialValues: true,
+        detectObjects: false,
+      }],
+      // R2 self-validating types: parse at the boundary
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'error',
+      '@typescript-eslint/no-unsafe-assignment': 'error',
+      '@typescript-eslint/no-unsafe-call': 'error',
+      '@typescript-eslint/no-unsafe-member-access': 'error',
+      '@typescript-eslint/no-unsafe-return': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'error',
+      // R5 vertical slice: one juicy module per file; counts code lines only
+      'sonarjs/max-lines': ['error', { maximum: 450 }],
+      'react/no-multi-comp': ['error', { ignoreStateless: false }],
+      // R8 no globals
+      'import/no-mutable-exports': 'error',
+      // R10 concurrency safety
+      'react-hooks/exhaustive-deps': 'error',
+      'react-hooks/set-state-in-effect': 'error',
+      '@typescript-eslint/no-floating-promises': 'error',
+      '@typescript-eslint/no-misused-promises': 'error',
+      'promise/catch-or-return': 'error',
+      // R11 conditional dispatch
+      '@typescript-eslint/switch-exhaustiveness-check': 'error',
+      'sonarjs/no-nested-switch': 'error',
+      'sonarjs/max-switch-cases': 'error',
+      'sonarjs/no-small-switch': 'error',
+      // R12 mutation discipline
+      'no-param-reassign': ['error', { props: true }],
+      'sonarjs/prefer-read-only-props': 'error',
+      'react/no-direct-mutation-state': 'error',
+    },
+  },
+  {
+    // Tests are long and repeat literals by design.
+    files: ['**/*.test.{ts,tsx}', '**/*.spec.{ts,tsx}'],
+    rules: {
+      'sonarjs/max-lines-per-function': 'off',
+      'sonarjs/no-duplicate-string': 'off',
+      'sonarjs/no-nested-functions': 'off',
+      'max-params': 'off',
+      'no-magic-numbers': 'off',
+      'react/no-multi-comp': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+]
diff --git a/go-linter-driven-development/setup/golangci.yaml b/go-linter-driven-development/setup/golangci.yaml
new file mode 100644
index 0000000..fd73147
--- /dev/null
+++ b/go-linter-driven-development/setup/golangci.yaml
@@ -0,0 +1,86 @@
+# Recommended golangci-lint v2 configuration of the linter-driven-development
+# plugins: every linter rule the plugin's routing table routes to one of the
+# twelve design rules, at the limits the rules name. Each linter line says which
+# rule its failures feed. The plugin never writes this file into a repository:
+# the repository's owners copy it, or the parts they want, into .golangci.yaml.
+# residue-exempt: a golangci-lint configuration names its linters on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# naming, formatting) are the repository's own choice.
+#
+# Adopt it on an existing codebase with the ratchet below: only issues in code
+# changed since the merge base with main fail, so old code is not a wall of
+# findings on day one. CI needs main in the clone for it (fetch-depth: 0 in
+# GitHub Actions). Remove the ratchet once the old findings are gone.
+# gocyclo stands for the routing table's "gocyclo / cyclop": enable one of the two.
+
+version: "2"
+
+issues:
+  new-from-merge-base: main
+
+linters:
+  # The standard set (errcheck, govet, ineffassign, staticcheck, unused) stays on;
+  # the linters below are added to it.
+  default: standard
+  enable:
+    - gocyclo           # R3 storifying: cyclomatic complexity
+    - gocognit          # R3 storifying: cognitive complexity
+    - funlen            # R3 storifying: function length
+    - nestif            # R3 storifying: nesting depth
+    - maintidx          # R3 storifying, R1 types: maintainability index
+    - dupl              # R1 types: duplicated logic; a duplicated switch is R11
+    - exhaustive        # R11 conditional dispatch: missing enum cases
+    - gochecknoglobals  # R8 no globals
+    - gochecknoinits    # R8 no globals
+    - ireturn           # R6 test-only interfaces: a constructor that returns an interface
+    - govet             # R10 concurrency: copylocks
+    - revive            # R1 types, R5 vertical slice: the rules below
+    - errcheck          # mechanical: an error that is not handled
+    - wrapcheck         # mechanical: an error without the context of its layer
+    - goconst           # mechanical; an enum-shaped string is R1's "Name enum strings"
+  settings:
+    gocyclo:
+      min-complexity: 10
+    gocognit:
+      min-complexity: 15
+    funlen:
+      lines: 50
+      statements: 40
+    nestif:
+      min-complexity: 2
+    maintidx:
+      under: 20
+    dupl:
+      threshold: 100
+    exhaustive:
+      # A default branch does not count as handling a case: every new case is
+      # handled where the switch is.
+      default-signifies-exhaustive: false
+    govet:
+      enable:
+        - copylocks
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    revive:
+      rules:
+        - name: argument-limit          # R1: more than 4 parameters wants a parameter object
+          arguments: [4]
+        - name: function-result-limit   # R1: more than 3 results wants a named result type
+          arguments: [3]
+        - name: file-length-limit       # R5: one juicy type per file; counts code lines only
+          arguments: [{max: 450, skip-comments: true, skip-blank-lines: true}]
+        - name: early-return            # mechanical: invert the condition and return early
+  exclusions:
+    rules:
+      # Tests are long and repeat literals by design.
+      - path: _test\.go
+        linters:
+          - funlen
+          - gocognit
+          - gocyclo
+          - maintidx
+          - dupl
+          - goconst
diff --git a/go-linter-driven-development/setup/ruff.toml b/go-linter-driven-development/setup/ruff.toml
new file mode 100644
index 0000000..03571ca
--- /dev/null
+++ b/go-linter-driven-development/setup/ruff.toml
@@ -0,0 +1,58 @@
+# Recommended ruff configuration of the linter-driven-development plugins:
+# every rule the plugin's routing table routes to one of the twelve design
+# rules, at the limits the rules name. Each rule says which rule its failures
+# feed. The plugin never writes this file into a repository: the repository's
+# owners copy it, or the parts they want, into ruff.toml, or into
+# pyproject.toml with each table name prefixed by "tool.ruff." ([lint] becomes
+# [tool.ruff.lint]).
+# residue-exempt: a ruff configuration names its rule codes on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# docstrings, imports) are the repository's own choice. ruff has no file-length
+# rule: the plugin's gap linter, scripts/ldd-lint.sh file-length, holds that
+# limit at 450 code lines.
+#
+# Adopt it on an existing codebase one change at a time: run ruff on the files
+# changed since the merge base with main, so old code is not a wall of
+# findings on day one:
+#   git diff -z --name-only --diff-filter=d "$(git merge-base HEAD main)" -- '*.py' \
+#     | xargs -0 sh -c '[ "$#" -eq 0 ] || ruff check "$@"' sh
+# The sh guard keeps an empty change list from checking the whole repository,
+# and -z with -0 keeps a path with spaces whole.
+
+[lint]
+# PLR1702 (nested blocks) is a preview rule. Preview mode also turns on preview
+# behavior of the stable rules a repository already selects; a repository that
+# does not want that drops these two lines and PLR1702.
+preview = true
+explicit-preview-rules = true
+extend-select = [
+  "C901",     # R3 storifying: complexity
+  "PLR0911",  # R3 storifying: too many returns
+  "PLR0912",  # R3 storifying: too many branches
+  "PLR0915",  # R3 storifying: too many statements
+  "PLR1702",  # R3 storifying: nesting
+  "PLR0913",  # R1 types: too many arguments wants a parameter object
+  "PLR2004",  # R1 types: a magic value; an enum-shaped string is "Name enum strings"
+  "FBT001",   # R11 conditional dispatch: a boolean positional parameter
+  "FBT002",   # R11 conditional dispatch: a boolean default parameter
+  "PLW0603",  # R8 no globals: a global statement
+  "B006",     # R12 mutation discipline: a mutable default argument
+  "B008",     # R12 mutation discipline: a call in a default argument
+]
+
+[lint.mccabe]
+max-complexity = 8
+
+[lint.pylint]
+max-args = 4          # self and cls are not counted
+max-branches = 12
+max-returns = 6
+max-statements = 50
+max-nested-blocks = 2  # R3: more than 2 nesting levels
+
+[lint.per-file-ignores]
+# Tests repeat literals and take many fixtures by design.
+"**/test_*.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
+"**/*_test.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
diff --git a/lang/generic/passthrough/CHANGELOG.md b/lang/generic/passthrough/CHANGELOG.md
index 1befcfe..80a0749 100644
--- a/lang/generic/passthrough/CHANGELOG.md
+++ b/lang/generic/passthrough/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/lang/generic/passthrough/README.md b/lang/generic/passthrough/README.md
index bf11dbf..854826c 100644
--- a/lang/generic/passthrough/README.md
+++ b/lang/generic/passthrough/README.md
@@ -47,6 +47,11 @@ phase is exactly as strong as your repository's own linter configuration:
   invokes — `golangci-lint`, `ruff`, `eslint`, `clippy`, `checkstyle` — via the
   Taskfile, Makefile or package script that invokes it. It never installs or runs a
   linter the repository does not use.
+- **It ships a recommended setup for Go, Python and TypeScript.** `setup/` in the
+  plugin directory holds `golangci.yaml`, `ruff.toml` and `eslint.config.ldd.mjs`:
+  every linter rule the routing table routes to a design rule, at the limits the
+  rules name. The plugin never writes them into your repository: copy one, or the
+  parts you want. Limits your configuration already sets stay yours.
 - **It routes findings by what they are about.** The refactoring skill's routing
   table is keyed by finding family — complexity, function length, nesting,
   duplicated code, non-exhaustive switch, globals, single-implementation interfaces,
diff --git a/lang/generic/scripts/ldd-fixture.sh b/lang/generic/scripts/ldd-fixture.sh
index 6ae87c2..055ea51 100644
--- a/lang/generic/scripts/ldd-fixture.sh
+++ b/lang/generic/scripts/ldd-fixture.sh
@@ -18,6 +18,18 @@
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -35,6 +47,12 @@ use_row() {
   case "$1" in
     go)
       FX_LINTER_CONFIG='.golangci.yml'
+      FX_SETUP_FILE='golangci.yaml'
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE='file-length-limit'
       FX_LINTER_COMMENT='#'
       FX_EXT='.go'
       FX_LINE_COMMENT='// note'
@@ -47,6 +65,12 @@ use_row() {
       ;;
     python)
       FX_LINTER_CONFIG='.pylintrc'
+      FX_SETUP_FILE=''
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE=''
       FX_LINTER_COMMENT=';'
       FX_EXT='.py'
       FX_LINE_COMMENT='# note'
diff --git a/lang/go/passthrough/CHANGELOG.md b/lang/go/passthrough/CHANGELOG.md
index 36bff47..ef2e41a 100644
--- a/lang/go/passthrough/CHANGELOG.md
+++ b/lang/go/passthrough/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -33,6 +42,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/lang/go/passthrough/README.md b/lang/go/passthrough/README.md
index 5c15ab5..b7f0d41 100644
--- a/lang/go/passthrough/README.md
+++ b/lang/go/passthrough/README.md
@@ -209,7 +209,9 @@ Should show: `go-linter-driven-development (enabled)`
 
 The scenario guide — the easiest start first, then code you already wrote, a plan you already have, and running the plugin from a subagent — is [docs/quick-start.md](https://github.com/buzzdan/ai-coding-rules/blob/main/docs/quick-start.md) in the main repository.
 
-**Zero configuration required.** The plugin discovers your project's test and lint commands from `README.md`, `CLAUDE.md`, `Makefile`, or `Taskfile.yaml`. Just install and go.
+**Zero configuration to run.** The plugin discovers your project's test and lint commands from `README.md`, `CLAUDE.md`, `Makefile`, or `Taskfile.yaml`. Just install and go.
+
+**The recommended setup makes the design triggers fire.** `setup/golangci.yaml` in the plugin directory enables every linter the routing table routes to a design rule, at the limits the rules name, with a ratchet so only new code fails at first. The plugin never writes it into your repository: copy it, or the parts you want, into `.golangci.yaml`. Limits your configuration already sets stay yours.
 
 ### The Easiest Way: Just Talk to It
 
diff --git a/lang/go/scripts/ldd-fixture.sh b/lang/go/scripts/ldd-fixture.sh
index d437f89..10f15e3 100644
--- a/lang/go/scripts/ldd-fixture.sh
+++ b/lang/go/scripts/ldd-fixture.sh
@@ -18,6 +18,18 @@
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -33,6 +45,13 @@ FX_NATIVE="go"
 
 use_row() {
   FX_LINTER_CONFIG='.golangci.yaml'
+  FX_SETUP_FILE='golangci.yaml'
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='golangci.yaml'
+  FX_RULE_ID_RE='^[a-z][a-z0-9-]*$'
+  # cyclop is the alternative to gocyclo; package-size is the gap linter's
+  FX_ROUTED_SKIP='cyclop package-size'
+  FX_LENGTH_RULE='file-length-limit'
   FX_LINTER_COMMENT='#'
   FX_EXT='.go'
   FX_LINE_COMMENT='// note'
diff --git a/lang/python/passthrough/CHANGELOG.md b/lang/python/passthrough/CHANGELOG.md
index 380c0df..1d8d852 100644
--- a/lang/python/passthrough/CHANGELOG.md
+++ b/lang/python/passthrough/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/lang/python/passthrough/README.md b/lang/python/passthrough/README.md
index 762721b..5c3af42 100644
--- a/lang/python/passthrough/README.md
+++ b/lang/python/passthrough/README.md
@@ -98,9 +98,15 @@ checker the repository does not use.
   `PLR0913` to R1, `PLW0603` to R8, `FBT` to R11, `B006`/`B008` to R12. The
   mechanical row — `ARG`, `SIM`, `RET`, `B904`, `BLE001`, `PLR2004`, import order,
   style — is fixed by the lint-fixer in an isolated context.
-- **Some findings have no ruff rule.** Duplicated code, file length, a `match`
-  missing enum cases, a `Protocol` with one implementer and shared-state races are
-  review findings: the hunters own them alone.
+- **Some findings have no ruff rule.** Duplicated code, a `match` missing enum
+  cases, a `Protocol` with one implementer and shared-state races are review
+  findings: the hunters own them alone. File length has no ruff rule either: the
+  gap linter, `scripts/ldd-lint.sh file-length`, measures it.
+- **The recommended setup makes the design triggers fire.** `setup/ruff.toml` in the
+  plugin directory selects every ruff rule the routing table routes to a design
+  rule, at the limits the rules name. The plugin never writes it into your
+  repository: copy it, or the parts you want, into `ruff.toml` or `pyproject.toml`.
+  Limits your configuration already sets stay yours.
 - **`# noqa`, `# ty: ignore` and `# type: ignore` are all suppressions.** The lint-fixer
   never adds one and never edits `[tool.ruff]`, `[tool.ty]` or `[tool.mypy]`; a new
   one in a diff is itself a review finding.
diff --git a/lang/python/scripts/ldd-fixture.sh b/lang/python/scripts/ldd-fixture.sh
index c900020..5645170 100644
--- a/lang/python/scripts/ldd-fixture.sh
+++ b/lang/python/scripts/ldd-fixture.sh
@@ -18,6 +18,18 @@
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -33,6 +45,12 @@ FX_NATIVE="python"
 
 use_row() {
   FX_LINTER_CONFIG='pyproject.toml'
+  FX_SETUP_FILE=''
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='ruff.toml'
+  FX_RULE_ID_RE='^[A-Z]+[0-9]+$'
+  FX_ROUTED_SKIP=''
+  FX_LENGTH_RULE=''
   FX_LINTER_COMMENT='#'
   FX_EXT='.py'
   FX_LINE_COMMENT='# note'
diff --git a/lang/ts-react/passthrough/CHANGELOG.md b/lang/ts-react/passthrough/CHANGELOG.md
index d4d78ed..a452a3a 100644
--- a/lang/ts-react/passthrough/CHANGELOG.md
+++ b/lang/ts-react/passthrough/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/lang/ts-react/passthrough/README.md b/lang/ts-react/passthrough/README.md
index a0498f2..3117d92 100644
--- a/lang/ts-react/passthrough/README.md
+++ b/lang/ts-react/passthrough/README.md
@@ -142,6 +142,12 @@ adds a checker the repository does not use.
   `@ts-expect-error`, `@ts-ignore`, `@ts-nocheck` and `// prettier-ignore`. The
   lint-fixer never adds one and never edits `eslint.config.*`, `tsconfig*.json` or
   `.prettierrc*`; a new one in a diff is itself a review finding.
+- **The recommended setup makes the design triggers fire.** `setup/eslint.config.ldd.mjs`
+  in the plugin directory is a flat-config fragment with every rule the routing
+  table routes to a design rule, at the limits the rules name. The plugin never
+  writes it into your repository: copy it beside `eslint.config.js` and spread it
+  before your own entries, so every limit your configuration already sets stays
+  yours.
 - **What it does not review.** Accessibility beyond what `jsx-a11y` flags —
   contrast, heading order, focus management, live regions — is the repository's
   axe run, which this plugin does not replace. Error-boundary placement and
diff --git a/lang/ts-react/scripts/ldd-fixture.sh b/lang/ts-react/scripts/ldd-fixture.sh
index aa24553..3d57f0c 100644
--- a/lang/ts-react/scripts/ldd-fixture.sh
+++ b/lang/ts-react/scripts/ldd-fixture.sh
@@ -18,6 +18,18 @@
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -36,6 +48,14 @@ FX_NATIVE="typescript"
 # Every file the row writes is a `.ts` file, so both globs select the same set.
 use_row() {
   FX_LINTER_CONFIG='eslint.config.mjs'
+  FX_SETUP_FILE='eslint.config.ldd.mjs'
+  FX_ADOPTED_CONFIG='eslint.config.ldd.mjs'
+  FX_ROUTED_FILE='eslint.config.ldd.mjs'
+  FX_RULE_ID_RE='^(@[a-z-]+/)?[a-z-]+(/[a-z*-]+)?$'
+  # no-restricted-syntax needs the repository's config module path;
+  # package-size is the gap linter's
+  FX_ROUTED_SKIP='no-restricted-syntax package-size'
+  FX_LENGTH_RULE='sonarjs/max-lines'
   FX_LINTER_COMMENT='//'
   FX_EXT='.ts'
   FX_LINE_COMMENT='// note'
diff --git a/linter-driven-development/CHANGELOG.md b/linter-driven-development/CHANGELOG.md
index 1befcfe..80a0749 100644
--- a/linter-driven-development/CHANGELOG.md
+++ b/linter-driven-development/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/linter-driven-development/README.md b/linter-driven-development/README.md
index bf11dbf..854826c 100644
--- a/linter-driven-development/README.md
+++ b/linter-driven-development/README.md
@@ -47,6 +47,11 @@ phase is exactly as strong as your repository's own linter configuration:
   invokes — `golangci-lint`, `ruff`, `eslint`, `clippy`, `checkstyle` — via the
   Taskfile, Makefile or package script that invokes it. It never installs or runs a
   linter the repository does not use.
+- **It ships a recommended setup for Go, Python and TypeScript.** `setup/` in the
+  plugin directory holds `golangci.yaml`, `ruff.toml` and `eslint.config.ldd.mjs`:
+  every linter rule the routing table routes to a design rule, at the limits the
+  rules name. The plugin never writes them into your repository: copy one, or the
+  parts you want. Limits your configuration already sets stay yours.
 - **It routes findings by what they are about.** The refactoring skill's routing
   table is keyed by finding family — complexity, function length, nesting,
   duplicated code, non-exhaustive switch, globals, single-implementation interfaces,
diff --git a/linter-driven-development/scripts/ldd-detect_test.sh b/linter-driven-development/scripts/ldd-detect_test.sh
index 8e1c887..fe0cfc7 100644
--- a/linter-driven-development/scripts/ldd-detect_test.sh
+++ b/linter-driven-development/scripts/ldd-detect_test.sh
@@ -141,6 +141,18 @@ questions_in_rules() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -158,6 +170,12 @@ use_row() {
   case "$1" in
     go)
       FX_LINTER_CONFIG='.golangci.yml'
+      FX_SETUP_FILE='golangci.yaml'
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE='file-length-limit'
       FX_LINTER_COMMENT='#'
       FX_EXT='.go'
       FX_LINE_COMMENT='// note'
@@ -170,6 +188,12 @@ use_row() {
       ;;
     python)
       FX_LINTER_CONFIG='.pylintrc'
+      FX_SETUP_FILE=''
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE=''
       FX_LINTER_COMMENT=';'
       FX_EXT='.py'
       FX_LINE_COMMENT='# note'
diff --git a/linter-driven-development/scripts/ldd-lint.sh b/linter-driven-development/scripts/ldd-lint.sh
index c0252a3..a8d34d6 100755
--- a/linter-driven-development/scripts/ldd-lint.sh
+++ b/linter-driven-development/scripts/ldd-lint.sh
@@ -338,9 +338,15 @@ lang_is_test() {
 #                                   nothing. A named rule belongs to the linter:
 #                                   its limit, its counting and whether it is on
 #                                   are the repository's decision.
-#   lint_file_length_snippet <id> <max>  the linter setting that would hold the
-#                                   limit, or the .ldd-lint.yaml entry when no
-#                                   linter rule is known: text to propose
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
 
 lint_comment_style() {
   case "$1" in
@@ -429,8 +435,10 @@ lint_file_length_rule() {
       f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
         && printf 'revive file-length-limit in %s' "$f" ;;
     typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
       local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
-                     .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
       if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
         printf 'sonarjs/max-lines in %s' "$f"
       elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
@@ -443,12 +451,27 @@ lint_file_length_rule() {
   return 0
 }
 
-lint_file_length_snippet() {
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
   case "$1" in
-    go)                    printf "revive in .golangci.yaml: - name: file-length-limit, arguments: [{max: %s, skip-comments: true, skip-blank-lines: true}]" "$2" ;;
-    typescript|javascript) printf "the eslint config: 'sonarjs/max-lines': ['error', { maximum: %s }]" "$2" ;;
-    python)                printf "pyproject.toml: [tool.pylint.format] max-module-lines = %s (pylint counts every line, comments and blank lines too)" "$2" ;;
-    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: %s would state this limit" "$1" "$2" ;;
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
   esac
 }
 # ================== end linter table ==================
@@ -520,6 +543,16 @@ trap 'rm -f "$SCOPE" "$INVENTORY"' EXIT
 list_candidates | by_language > "$SCOPE"
 if [[ -n "$FILES_LIST" ]]; then list_repo | by_language > "$INVENTORY"; else cp "$SCOPE" "$INVENTORY"; fi
 
+# dir_of <path> — the directory part of a relative path, "." for a file at
+# the root. A function, because bash 3.2 misreads a case pattern's ")" inside
+# a process substitution.
+dir_of() {
+  case "$1" in
+    */*) printf '%s\n' "${1%/*}" ;;
+    *)   printf '.\n' ;;
+  esac
+}
+
 # measured <path> — exit 0 when the file counts for this language: not under
 # an excluded directory, not a test, not generated. Every path the script
 # hands to find, head or awk starts with "./", and a directory is cut from a
@@ -551,7 +584,7 @@ run_file_length() { # <id> — every measured file of that language
     say "threshold: $id file length — set by $OVERRIDE_FILE ($max code lines)"
   else
     max="$DEFAULT_FILE_MAX_LINES"; src="profile default"
-    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; a setting to propose, never to add on your own: $(lint_file_length_snippet "$id" "$max")"
+    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; $(lint_file_length_proposal "$id")"
   fi
   while IFS=$'\t' read -r _ f; do
     measured "$f" || continue
@@ -575,7 +608,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
   awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$INVENTORY" | while IFS= read -r f; do
     [[ -n "$skip" ]] && printf '%s\n' "$f" | grep -qE -- "$skip" && continue
     measured "$f" || continue
-    case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+    dir_of "$f"
   done | LC_ALL=C sort | uniq -c | awk '{ n = $1; sub(/^[ \t]*[0-9]+[ \t]/, ""); print $0 "\t" n }' > "$counts"
   while IFS= read -r d; do
     n=$(awk -F'\t' -v d="$d" '$1 == d { print $2; exit }' "$counts")
@@ -586,8 +619,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
       finding "$d" "$n source files (warning at $warn, $src)"
     fi
   done < <(awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$SCOPE" | while IFS= read -r f; do
-             measured "$f" || continue
-             case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+             measured "$f" && dir_of "$f"
            done | LC_ALL=C sort -u)
   rm -f "$counts"
 }
diff --git a/linter-driven-development/scripts/ldd-lint_test.sh b/linter-driven-development/scripts/ldd-lint_test.sh
index 962c198..99f31f9 100644
--- a/linter-driven-development/scripts/ldd-lint_test.sh
+++ b/linter-driven-development/scripts/ldd-lint_test.sh
@@ -105,6 +105,18 @@ fill_dir() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -122,6 +134,12 @@ use_row() {
   case "$1" in
     go)
       FX_LINTER_CONFIG='.golangci.yml'
+      FX_SETUP_FILE='golangci.yaml'
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE='file-length-limit'
       FX_LINTER_COMMENT='#'
       FX_EXT='.go'
       FX_LINE_COMMENT='// note'
@@ -134,6 +152,12 @@ use_row() {
       ;;
     python)
       FX_LINTER_CONFIG='.pylintrc'
+      FX_SETUP_FILE=''
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE=''
       FX_LINTER_COMMENT=';'
       FX_EXT='.py'
       FX_LINE_COMMENT='# note'
@@ -241,6 +265,167 @@ fx_write_linter_config_other() {
   esac
 }
 
+# ==================== linter table ====================
+# What the gap linter needs to know per language id: how a comment is written,
+# which source files a directory count leaves out, and whether the
+# repository's own linter holds the file-length limit. The same table is
+# rendered into every plugin, so two plugins measure one file the same way.
+# residue-exempt: the table names every language's linter and config file on
+# purpose, the same in every rendering.
+#
+#   lint_comment_style <id>         c (// and /* */), d (also /+ +/) or hash (#)
+#   lint_strip_comments <style> <file>  the file with every comment removed and
+#                                   string literals kept, one output line per
+#                                   input line: a comment-only line prints empty.
+#                                   Styles: c, d, hash (# and triple-quoted
+#                                   strings), ini (# and a leading ;)
+#   lint_package_skip_re <id>       ERE over a relative path: source files a
+#                                   directory count leaves out (an index module,
+#                                   a package marker, generated stubs); "" for none
+#   lint_file_length_rule <id>      "<rule> in <config file>" when a linter config
+#                                   at the repository root names a file-length
+#                                   rule outside a comment, else
+#                                   nothing. A named rule belongs to the linter:
+#                                   its limit, its counting and whether it is on
+#                                   are the repository's decision.
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
+
+lint_comment_style() {
+  case "$1" in
+    python|ruby|shell) printf 'hash' ;;
+    d)                 printf 'd' ;;
+    *)                 printf 'c' ;;
+  esac
+}
+
+lint_package_skip_re() {
+  case "$1" in
+    go)                    printf '%s' '(_gen|\.pb)\.go$' ;;
+    python)                printf '%s' '(^|/)(__init__|conftest)\.py$|_pb2(_grpc)?\.py$' ;;
+    typescript|javascript) printf '%s' '(^|/)index\.[cm]?[jt]sx?$|\.stories\.[cm]?[jt]sx?$' ;;
+  esac
+  return 0
+}
+
+# LINT_STRIP_AWK walks each line one character at a time. A quote opens a
+# string that a comment marker cannot end; single and double quotes close at
+# the end of the line, a backtick string (c and d) and a triple-quoted string
+# (hash) run on. A block comment may open after code and run on. The awk uses
+# substr and string compares only, so mawk, gawk and BSD awk read it alike.
+LINT_STRIP_AWK='
+BEGIN { bq = sprintf("%c", 96); sq = sprintf("%c", 39); dq = "\"" }
+{
+  line = $0; out = ""; n = length(line); i = 1
+  if (q == dq || q == sq) q = ""
+  while (i <= n) {
+    if (inblock) {
+      if (substr(line, i, length(closer)) == closer) { inblock = 0; i += length(closer); out = out " "; continue }
+      i++; continue
+    }
+    ch = substr(line, i, 1)
+    if (q != "") {
+      if (ch == "\\" && (q == dq || q == sq)) { out = out substr(line, i, 2); i += 2; continue }
+      if (substr(line, i, length(q)) == q) { out = out q; i += length(q); q = ""; continue }
+      out = out ch; i++; continue
+    }
+    if (style == "hash" || style == "ini") {
+      if (ch == "#") break
+      if (style == "ini" && ch == ";" && out ~ /^[ \t]*$/) break
+      three = substr(line, i, 3)
+      if (style == "hash" && (three == dq dq dq || three == sq sq sq)) { q = three; out = out three; i += 3; continue }
+    } else {
+      two = substr(line, i, 2)
+      if (two == "//") break
+      if (two == "/*" || (style == "d" && two == "/+")) { inblock = 1; closer = (two == "/+") ? "+/" : "*/"; out = out " "; i += 2; continue }
+      if (ch == bq) { q = bq; out = out ch; i++; continue }
+    }
+    if (ch == dq || ch == sq) { q = ch; out = out ch; i++; continue }
+    out = out ch; i++
+  }
+  print out
+}
+'
+
+lint_strip_comments() { # <style> <file>
+  awk -v style="$1" "$LINT_STRIP_AWK" "$2"
+}
+
+# _lint_config_style <config file> — how that config format writes a comment
+_lint_config_style() {
+  case "$1" in
+    *.yaml|*.yml|*.toml) printf 'hash' ;;
+    *.cfg|*.ini|.pylintrc|pylintrc) printf 'ini' ;;
+    *) printf 'c' ;;
+  esac
+}
+
+# _lint_names <ERE> <file>... — print the first file whose text outside its
+# comments matches the pattern
+_lint_names() {
+  local re="$1" f; shift
+  for f in "$@"; do
+    [[ -f "$f" ]] || continue
+    lint_strip_comments "$(_lint_config_style "$f")" "./$f" 2>/dev/null | grep -qE -- "$re" && { printf '%s' "$f"; return 0; }
+  done
+  return 1
+}
+
+lint_file_length_rule() {
+  local f
+  case "$1" in
+    go)
+      f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
+        && printf 'revive file-length-limit in %s' "$f" ;;
+    typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
+      local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+      if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'sonarjs/max-lines in %s' "$f"
+      elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'max-lines in %s' "$f"
+      fi ;;
+    python)
+      f=$(_lint_names '^[[:space:]]*max-module-lines[[:space:]]*=' pyproject.toml .pylintrc pylintrc setup.cfg tox.ini) \
+        && printf 'pylint max-module-lines in %s' "$f" ;;
+  esac
+  return 0
+}
+
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
+  case "$1" in
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
+  esac
+}
+# ================== end linter table ==================
+
 # ========================= cases =========================
 run_row_cases() { # runs every case against the current row
 
@@ -300,7 +485,16 @@ finish
 begin "the plugin's default names a linter setting to propose, never to add"
 write_src "src/a$FX_EXT" 1
 run_lint file-length
-expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a setting to propose, never to add on your own: " && ok
+SETUP_DIR="$(dirname "$LINT")/../setup"
+if [[ -n "$FX_SETUP_FILE" ]]; then
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" \
+    && expect_has "a setting to propose, never to add on your own: " \
+    && expect_has "$FX_LENGTH_RULE, as the plugin's setup/$FX_SETUP_FILE sets it" \
+    && { grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && grep -q -- "$MAX_LINES" "$SETUP_DIR/$FX_SETUP_FILE" || bad "setup/$FX_SETUP_FILE does not set $FX_LENGTH_RULE at $MAX_LINES"; } \
+    && grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && ok
+else
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a .ldd-lint.yaml entry file_max_lines" && ok
+fi
 finish
 
 begin "a file-length rule in the linter config hands file length to the linter"
@@ -332,6 +526,39 @@ run_lint file-length
 expect_exit 0 && expect_not "held by " && expect_has "src/over$FX_EXT: $((MAX_LINES + 1)) code lines" && ok
 finish
 
+begin "the recommended config enables every rule the routing table routes to a design rule"
+if [[ -z "$FX_ROUTED_FILE" ]]; then skip "this plugin's routing table names no linter rule"; finish
+else
+  table=$(grep -l '^| Linter failure | Route |' "$(dirname "$LINT")"/../skills/refactoring/*.md | head -1)
+  missing=""; checked=0
+  while IFS= read -r id; do
+    case " $FX_ROUTED_SKIP " in *" $id "*) continue ;; esac
+    checked=$((checked + 1))
+    case "$id" in
+      *'*') re="(^|[^A-Za-z0-9/@-])${id%\*}" ;;
+      *)    re="(^|[^A-Za-z0-9/@-])${id}([^A-Za-z0-9/-]|\$)" ;;
+    esac
+    grep -qE -- "$re" "$(dirname "$LINT")/../setup/$FX_ROUTED_FILE" || missing="$missing $id"
+  done < <(awk -F'|' '
+      /^\| Linter failure \| Route \|/ { t = 1; next }
+      t && /^\|---/ { next }
+      t && /^\|/ { if ($3 ~ /rules\/R/) { c = $2; while (match(c, /`[^`]+`/)) { print substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) } } next }
+      t { t = 0 }' "$table" | grep -E -- "$FX_RULE_ID_RE" | LC_ALL=C sort -u)
+  { [[ -n "$table" ]] && (( checked > 0 )) || bad "no routed rule id found in the routing table"; } \
+    && { [[ -z "$missing" ]] || bad "setup/$FX_ROUTED_FILE lacks:$missing"; } && [[ -z "$missing" ]] && ok
+  finish
+fi
+
+begin "the recommended fragment, kept as its own file and imported, hands file length to the linter"
+if [[ -z "$FX_ADOPTED_CONFIG" ]]; then skip "this language's setup is copied into the linter's own config"; finish
+else
+  cp "$(dirname "$LINT")/../setup/$FX_ADOPTED_CONFIG" "$REPO/$FX_ADOPTED_CONFIG"
+  write_src "src/over$FX_EXT" $((MAX_LINES + 50))
+  run_lint file-length
+  expect_exit 0 && expect_has "held by " && expect_has "in $FX_ADOPTED_CONFIG" && expect_no_finding && ok
+  finish
+fi
+
 begin ".ldd-lint.yaml sets the limit when the linter holds none"
 printf 'file_max_lines: 100  # this repository\n' > "$REPO/.ldd-lint.yaml"
 write_src "src/a$FX_EXT" 101
@@ -470,6 +697,18 @@ for opt in --root --files --glob --test-re; do
   finish
 done
 
+# --- the recommended configs under setup/, checked by their own linters when
+# the machine has them ---
+SETUP_DIR="$(dirname "$LINT")/../setup"
+
+while IFS=$'\t' read -r setup_file setup_tool; do
+  begin "setup/$setup_file passes its own linter's check"
+  if ! command -v "$setup_tool" >/dev/null 2>&1; then skip "$setup_tool is not on PATH"; finish; continue; fi
+  OUT=$(lint_setup_check "$setup_file" "$SETUP_DIR" "$REPO" 2>&1); CODE=$?; ERR=""
+  expect_exit 0 && ok
+  finish
+done < <(lint_setup_files)
+
 # ========================= summary =========================
 echo
 echo "ldd-lint_test: $pass passed, $failed failed, $skipped skipped"
diff --git a/linter-driven-development/scripts/ldd-scope_test.sh b/linter-driven-development/scripts/ldd-scope_test.sh
index fe40f58..9ef9d3b 100755
--- a/linter-driven-development/scripts/ldd-scope_test.sh
+++ b/linter-driven-development/scripts/ldd-scope_test.sh
@@ -117,6 +117,18 @@ mk_repo() { fx_write_marker "$REPO" fixture; fx_write_code; mk_docs; }
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -134,6 +146,12 @@ use_row() {
   case "$1" in
     go)
       FX_LINTER_CONFIG='.golangci.yml'
+      FX_SETUP_FILE='golangci.yaml'
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE='file-length-limit'
       FX_LINTER_COMMENT='#'
       FX_EXT='.go'
       FX_LINE_COMMENT='// note'
@@ -146,6 +164,12 @@ use_row() {
       ;;
     python)
       FX_LINTER_CONFIG='.pylintrc'
+      FX_SETUP_FILE=''
+      FX_ADOPTED_CONFIG=''
+      FX_ROUTED_FILE=''
+      FX_RULE_ID_RE=''
+      FX_ROUTED_SKIP=''
+      FX_LENGTH_RULE=''
       FX_LINTER_COMMENT=';'
       FX_EXT='.py'
       FX_LINE_COMMENT='# note'
diff --git a/linter-driven-development/setup/eslint.config.ldd.mjs b/linter-driven-development/setup/eslint.config.ldd.mjs
new file mode 100644
index 0000000..85da438
--- /dev/null
+++ b/linter-driven-development/setup/eslint.config.ldd.mjs
@@ -0,0 +1,115 @@
+// Recommended ESLint flat-config fragment of the linter-driven-development
+// plugins: every rule the plugin's routing table routes to one of the twelve
+// design rules, at the limits the rules name. Each rule line says which rule its
+// failures feed. The plugin never writes this file into a repository: the
+// repository's owners copy it, or the parts they want, beside eslint.config.js
+// and spread it before their own entries. Later entries win, so every limit the
+// repository's config already sets stays the repository's:
+//
+//   import ldd from './eslint.config.ldd.mjs'
+//   export default [...ldd, ...yourConfig]
+//
+// residue-exempt: an ESLint configuration names its plugins and rules on purpose.
+// It needs eslint-plugin-sonarjs, eslint-plugin-react, eslint-plugin-react-hooks,
+// eslint-plugin-promise, eslint-plugin-import and typescript-eslint; a repository
+// that does not use one of them leaves its rules out. The @typescript-eslint rules
+// below need type information: the repository's config sets typescript-eslint's
+// parser with parserOptions.projectService for these files, or ESLint stops with
+// an error. Limits a repository already sets stay the repository's: the linter is
+// the authority for every threshold it holds. Rules this file leaves out (style,
+// imports, formatting) are the repository's own choice, and so is
+// no-restricted-syntax on import.meta.env outside the config module (R8): the
+// config module's path is the repository's.
+//
+// Adopt it on an existing codebase with ESLint's bulk suppressions: run
+// `npx eslint --suppress-all` once to record today's violations, so only new ones
+// fail; `npx eslint --prune-suppressions` drops the entries that are fixed.
+
+import importPlugin from 'eslint-plugin-import'
+import promise from 'eslint-plugin-promise'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import sonarjs from 'eslint-plugin-sonarjs'
+import tseslint from 'typescript-eslint'
+
+export default [
+  {
+    files: ['**/*.{ts,tsx}'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+      import: importPlugin,
+      promise,
+      react,
+      'react-hooks': reactHooks,
+      sonarjs,
+    },
+    rules: {
+      // R3 storifying
+      'sonarjs/cognitive-complexity': ['error', 15],
+      'sonarjs/cyclomatic-complexity': ['error', { threshold: 10 }],
+      'sonarjs/expression-complexity': ['error', { max: 5 }],
+      // R3's limits: more than 50 lines or more than 2 nesting levels
+      'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],
+      'sonarjs/nested-control-flow': ['error', { maximumNestingLevel: 2 }],
+      'sonarjs/no-nested-conditional': 'error',
+      'sonarjs/no-nested-functions': 'error',
+      'sonarjs/elseif-without-else': 'error',
+      'react/no-unstable-nested-components': 'error',
+      // R1 primitive obsession
+      'max-params': ['error', 4],
+      'sonarjs/no-duplicate-string': ['error', { threshold: 3 }],
+      'sonarjs/max-union-size': ['error', { threshold: 4 }],
+      'sonarjs/no-identical-functions': 'error',
+      'react/no-array-index-key': 'error',
+      'no-magic-numbers': ['error', {
+        ignore: [-1, 0, 1, 2],
+        ignoreArrayIndexes: true,
+        ignoreDefaultValues: true,
+        ignoreClassFieldInitialValues: true,
+        detectObjects: false,
+      }],
+      // R2 self-validating types: parse at the boundary
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'error',
+      '@typescript-eslint/no-unsafe-assignment': 'error',
+      '@typescript-eslint/no-unsafe-call': 'error',
+      '@typescript-eslint/no-unsafe-member-access': 'error',
+      '@typescript-eslint/no-unsafe-return': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'error',
+      // R5 vertical slice: one juicy module per file; counts code lines only
+      'sonarjs/max-lines': ['error', { maximum: 450 }],
+      'react/no-multi-comp': ['error', { ignoreStateless: false }],
+      // R8 no globals
+      'import/no-mutable-exports': 'error',
+      // R10 concurrency safety
+      'react-hooks/exhaustive-deps': 'error',
+      'react-hooks/set-state-in-effect': 'error',
+      '@typescript-eslint/no-floating-promises': 'error',
+      '@typescript-eslint/no-misused-promises': 'error',
+      'promise/catch-or-return': 'error',
+      // R11 conditional dispatch
+      '@typescript-eslint/switch-exhaustiveness-check': 'error',
+      'sonarjs/no-nested-switch': 'error',
+      'sonarjs/max-switch-cases': 'error',
+      'sonarjs/no-small-switch': 'error',
+      // R12 mutation discipline
+      'no-param-reassign': ['error', { props: true }],
+      'sonarjs/prefer-read-only-props': 'error',
+      'react/no-direct-mutation-state': 'error',
+    },
+  },
+  {
+    // Tests are long and repeat literals by design.
+    files: ['**/*.test.{ts,tsx}', '**/*.spec.{ts,tsx}'],
+    rules: {
+      'sonarjs/max-lines-per-function': 'off',
+      'sonarjs/no-duplicate-string': 'off',
+      'sonarjs/no-nested-functions': 'off',
+      'max-params': 'off',
+      'no-magic-numbers': 'off',
+      'react/no-multi-comp': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+]
diff --git a/linter-driven-development/setup/golangci.yaml b/linter-driven-development/setup/golangci.yaml
new file mode 100644
index 0000000..fd73147
--- /dev/null
+++ b/linter-driven-development/setup/golangci.yaml
@@ -0,0 +1,86 @@
+# Recommended golangci-lint v2 configuration of the linter-driven-development
+# plugins: every linter rule the plugin's routing table routes to one of the
+# twelve design rules, at the limits the rules name. Each linter line says which
+# rule its failures feed. The plugin never writes this file into a repository:
+# the repository's owners copy it, or the parts they want, into .golangci.yaml.
+# residue-exempt: a golangci-lint configuration names its linters on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# naming, formatting) are the repository's own choice.
+#
+# Adopt it on an existing codebase with the ratchet below: only issues in code
+# changed since the merge base with main fail, so old code is not a wall of
+# findings on day one. CI needs main in the clone for it (fetch-depth: 0 in
+# GitHub Actions). Remove the ratchet once the old findings are gone.
+# gocyclo stands for the routing table's "gocyclo / cyclop": enable one of the two.
+
+version: "2"
+
+issues:
+  new-from-merge-base: main
+
+linters:
+  # The standard set (errcheck, govet, ineffassign, staticcheck, unused) stays on;
+  # the linters below are added to it.
+  default: standard
+  enable:
+    - gocyclo           # R3 storifying: cyclomatic complexity
+    - gocognit          # R3 storifying: cognitive complexity
+    - funlen            # R3 storifying: function length
+    - nestif            # R3 storifying: nesting depth
+    - maintidx          # R3 storifying, R1 types: maintainability index
+    - dupl              # R1 types: duplicated logic; a duplicated switch is R11
+    - exhaustive        # R11 conditional dispatch: missing enum cases
+    - gochecknoglobals  # R8 no globals
+    - gochecknoinits    # R8 no globals
+    - ireturn           # R6 test-only interfaces: a constructor that returns an interface
+    - govet             # R10 concurrency: copylocks
+    - revive            # R1 types, R5 vertical slice: the rules below
+    - errcheck          # mechanical: an error that is not handled
+    - wrapcheck         # mechanical: an error without the context of its layer
+    - goconst           # mechanical; an enum-shaped string is R1's "Name enum strings"
+  settings:
+    gocyclo:
+      min-complexity: 10
+    gocognit:
+      min-complexity: 15
+    funlen:
+      lines: 50
+      statements: 40
+    nestif:
+      min-complexity: 2
+    maintidx:
+      under: 20
+    dupl:
+      threshold: 100
+    exhaustive:
+      # A default branch does not count as handling a case: every new case is
+      # handled where the switch is.
+      default-signifies-exhaustive: false
+    govet:
+      enable:
+        - copylocks
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    revive:
+      rules:
+        - name: argument-limit          # R1: more than 4 parameters wants a parameter object
+          arguments: [4]
+        - name: function-result-limit   # R1: more than 3 results wants a named result type
+          arguments: [3]
+        - name: file-length-limit       # R5: one juicy type per file; counts code lines only
+          arguments: [{max: 450, skip-comments: true, skip-blank-lines: true}]
+        - name: early-return            # mechanical: invert the condition and return early
+  exclusions:
+    rules:
+      # Tests are long and repeat literals by design.
+      - path: _test\.go
+        linters:
+          - funlen
+          - gocognit
+          - gocyclo
+          - maintidx
+          - dupl
+          - goconst
diff --git a/linter-driven-development/setup/ruff.toml b/linter-driven-development/setup/ruff.toml
new file mode 100644
index 0000000..03571ca
--- /dev/null
+++ b/linter-driven-development/setup/ruff.toml
@@ -0,0 +1,58 @@
+# Recommended ruff configuration of the linter-driven-development plugins:
+# every rule the plugin's routing table routes to one of the twelve design
+# rules, at the limits the rules name. Each rule says which rule its failures
+# feed. The plugin never writes this file into a repository: the repository's
+# owners copy it, or the parts they want, into ruff.toml, or into
+# pyproject.toml with each table name prefixed by "tool.ruff." ([lint] becomes
+# [tool.ruff.lint]).
+# residue-exempt: a ruff configuration names its rule codes on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# docstrings, imports) are the repository's own choice. ruff has no file-length
+# rule: the plugin's gap linter, scripts/ldd-lint.sh file-length, holds that
+# limit at 450 code lines.
+#
+# Adopt it on an existing codebase one change at a time: run ruff on the files
+# changed since the merge base with main, so old code is not a wall of
+# findings on day one:
+#   git diff -z --name-only --diff-filter=d "$(git merge-base HEAD main)" -- '*.py' \
+#     | xargs -0 sh -c '[ "$#" -eq 0 ] || ruff check "$@"' sh
+# The sh guard keeps an empty change list from checking the whole repository,
+# and -z with -0 keeps a path with spaces whole.
+
+[lint]
+# PLR1702 (nested blocks) is a preview rule. Preview mode also turns on preview
+# behavior of the stable rules a repository already selects; a repository that
+# does not want that drops these two lines and PLR1702.
+preview = true
+explicit-preview-rules = true
+extend-select = [
+  "C901",     # R3 storifying: complexity
+  "PLR0911",  # R3 storifying: too many returns
+  "PLR0912",  # R3 storifying: too many branches
+  "PLR0915",  # R3 storifying: too many statements
+  "PLR1702",  # R3 storifying: nesting
+  "PLR0913",  # R1 types: too many arguments wants a parameter object
+  "PLR2004",  # R1 types: a magic value; an enum-shaped string is "Name enum strings"
+  "FBT001",   # R11 conditional dispatch: a boolean positional parameter
+  "FBT002",   # R11 conditional dispatch: a boolean default parameter
+  "PLW0603",  # R8 no globals: a global statement
+  "B006",     # R12 mutation discipline: a mutable default argument
+  "B008",     # R12 mutation discipline: a call in a default argument
+]
+
+[lint.mccabe]
+max-complexity = 8
+
+[lint.pylint]
+max-args = 4          # self and cls are not counted
+max-branches = 12
+max-returns = 6
+max-statements = 50
+max-nested-blocks = 2  # R3: more than 2 nesting levels
+
+[lint.per-file-ignores]
+# Tests repeat literals and take many fixtures by design.
+"**/test_*.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
+"**/*_test.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
diff --git a/python-linter-driven-development/CHANGELOG.md b/python-linter-driven-development/CHANGELOG.md
index 380c0df..1d8d852 100644
--- a/python-linter-driven-development/CHANGELOG.md
+++ b/python-linter-driven-development/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/python-linter-driven-development/README.md b/python-linter-driven-development/README.md
index 762721b..5c3af42 100644
--- a/python-linter-driven-development/README.md
+++ b/python-linter-driven-development/README.md
@@ -98,9 +98,15 @@ checker the repository does not use.
   `PLR0913` to R1, `PLW0603` to R8, `FBT` to R11, `B006`/`B008` to R12. The
   mechanical row — `ARG`, `SIM`, `RET`, `B904`, `BLE001`, `PLR2004`, import order,
   style — is fixed by the lint-fixer in an isolated context.
-- **Some findings have no ruff rule.** Duplicated code, file length, a `match`
-  missing enum cases, a `Protocol` with one implementer and shared-state races are
-  review findings: the hunters own them alone.
+- **Some findings have no ruff rule.** Duplicated code, a `match` missing enum
+  cases, a `Protocol` with one implementer and shared-state races are review
+  findings: the hunters own them alone. File length has no ruff rule either: the
+  gap linter, `scripts/ldd-lint.sh file-length`, measures it.
+- **The recommended setup makes the design triggers fire.** `setup/ruff.toml` in the
+  plugin directory selects every ruff rule the routing table routes to a design
+  rule, at the limits the rules name. The plugin never writes it into your
+  repository: copy it, or the parts you want, into `ruff.toml` or `pyproject.toml`.
+  Limits your configuration already sets stay yours.
 - **`# noqa`, `# ty: ignore` and `# type: ignore` are all suppressions.** The lint-fixer
   never adds one and never edits `[tool.ruff]`, `[tool.ty]` or `[tool.mypy]`; a new
   one in a diff is itself a review finding.
diff --git a/python-linter-driven-development/scripts/ldd-detect_test.sh b/python-linter-driven-development/scripts/ldd-detect_test.sh
index 941acf9..739b371 100644
--- a/python-linter-driven-development/scripts/ldd-detect_test.sh
+++ b/python-linter-driven-development/scripts/ldd-detect_test.sh
@@ -141,6 +141,18 @@ questions_in_rules() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -156,6 +168,12 @@ FX_NATIVE="python"
 
 use_row() {
   FX_LINTER_CONFIG='pyproject.toml'
+  FX_SETUP_FILE=''
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='ruff.toml'
+  FX_RULE_ID_RE='^[A-Z]+[0-9]+$'
+  FX_ROUTED_SKIP=''
+  FX_LENGTH_RULE=''
   FX_LINTER_COMMENT='#'
   FX_EXT='.py'
   FX_LINE_COMMENT='# note'
diff --git a/python-linter-driven-development/scripts/ldd-lint.sh b/python-linter-driven-development/scripts/ldd-lint.sh
index 4fa1f97..bed3e0d 100755
--- a/python-linter-driven-development/scripts/ldd-lint.sh
+++ b/python-linter-driven-development/scripts/ldd-lint.sh
@@ -225,9 +225,15 @@ lang_is_test() {
 #                                   nothing. A named rule belongs to the linter:
 #                                   its limit, its counting and whether it is on
 #                                   are the repository's decision.
-#   lint_file_length_snippet <id> <max>  the linter setting that would hold the
-#                                   limit, or the .ldd-lint.yaml entry when no
-#                                   linter rule is known: text to propose
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
 
 lint_comment_style() {
   case "$1" in
@@ -316,8 +322,10 @@ lint_file_length_rule() {
       f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
         && printf 'revive file-length-limit in %s' "$f" ;;
     typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
       local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
-                     .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
       if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
         printf 'sonarjs/max-lines in %s' "$f"
       elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
@@ -330,12 +338,27 @@ lint_file_length_rule() {
   return 0
 }
 
-lint_file_length_snippet() {
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
   case "$1" in
-    go)                    printf "revive in .golangci.yaml: - name: file-length-limit, arguments: [{max: %s, skip-comments: true, skip-blank-lines: true}]" "$2" ;;
-    typescript|javascript) printf "the eslint config: 'sonarjs/max-lines': ['error', { maximum: %s }]" "$2" ;;
-    python)                printf "pyproject.toml: [tool.pylint.format] max-module-lines = %s (pylint counts every line, comments and blank lines too)" "$2" ;;
-    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: %s would state this limit" "$1" "$2" ;;
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
   esac
 }
 # ================== end linter table ==================
@@ -407,6 +430,16 @@ trap 'rm -f "$SCOPE" "$INVENTORY"' EXIT
 list_candidates | by_language > "$SCOPE"
 if [[ -n "$FILES_LIST" ]]; then list_repo | by_language > "$INVENTORY"; else cp "$SCOPE" "$INVENTORY"; fi
 
+# dir_of <path> — the directory part of a relative path, "." for a file at
+# the root. A function, because bash 3.2 misreads a case pattern's ")" inside
+# a process substitution.
+dir_of() {
+  case "$1" in
+    */*) printf '%s\n' "${1%/*}" ;;
+    *)   printf '.\n' ;;
+  esac
+}
+
 # measured <path> — exit 0 when the file counts for this language: not under
 # an excluded directory, not a test, not generated. Every path the script
 # hands to find, head or awk starts with "./", and a directory is cut from a
@@ -438,7 +471,7 @@ run_file_length() { # <id> — every measured file of that language
     say "threshold: $id file length — set by $OVERRIDE_FILE ($max code lines)"
   else
     max="$DEFAULT_FILE_MAX_LINES"; src="profile default"
-    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; a setting to propose, never to add on your own: $(lint_file_length_snippet "$id" "$max")"
+    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; $(lint_file_length_proposal "$id")"
   fi
   while IFS=$'\t' read -r _ f; do
     measured "$f" || continue
@@ -462,7 +495,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
   awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$INVENTORY" | while IFS= read -r f; do
     [[ -n "$skip" ]] && printf '%s\n' "$f" | grep -qE -- "$skip" && continue
     measured "$f" || continue
-    case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+    dir_of "$f"
   done | LC_ALL=C sort | uniq -c | awk '{ n = $1; sub(/^[ \t]*[0-9]+[ \t]/, ""); print $0 "\t" n }' > "$counts"
   while IFS= read -r d; do
     n=$(awk -F'\t' -v d="$d" '$1 == d { print $2; exit }' "$counts")
@@ -473,8 +506,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
       finding "$d" "$n source files (warning at $warn, $src)"
     fi
   done < <(awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$SCOPE" | while IFS= read -r f; do
-             measured "$f" || continue
-             case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+             measured "$f" && dir_of "$f"
            done | LC_ALL=C sort -u)
   rm -f "$counts"
 }
diff --git a/python-linter-driven-development/scripts/ldd-lint_test.sh b/python-linter-driven-development/scripts/ldd-lint_test.sh
index 2289c66..3e55303 100644
--- a/python-linter-driven-development/scripts/ldd-lint_test.sh
+++ b/python-linter-driven-development/scripts/ldd-lint_test.sh
@@ -105,6 +105,18 @@ fill_dir() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -120,6 +132,12 @@ FX_NATIVE="python"
 
 use_row() {
   FX_LINTER_CONFIG='pyproject.toml'
+  FX_SETUP_FILE=''
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='ruff.toml'
+  FX_RULE_ID_RE='^[A-Z]+[0-9]+$'
+  FX_ROUTED_SKIP=''
+  FX_LENGTH_RULE=''
   FX_LINTER_COMMENT='#'
   FX_EXT='.py'
   FX_LINE_COMMENT='# note'
@@ -174,6 +192,167 @@ fx_write_linter_config_other() {
   printf '[tool.pylint.design]\nmax-args = 4\n' > "$REPO/pyproject.toml"
 }
 
+# ==================== linter table ====================
+# What the gap linter needs to know per language id: how a comment is written,
+# which source files a directory count leaves out, and whether the
+# repository's own linter holds the file-length limit. The same table is
+# rendered into every plugin, so two plugins measure one file the same way.
+# residue-exempt: the table names every language's linter and config file on
+# purpose, the same in every rendering.
+#
+#   lint_comment_style <id>         c (// and /* */), d (also /+ +/) or hash (#)
+#   lint_strip_comments <style> <file>  the file with every comment removed and
+#                                   string literals kept, one output line per
+#                                   input line: a comment-only line prints empty.
+#                                   Styles: c, d, hash (# and triple-quoted
+#                                   strings), ini (# and a leading ;)
+#   lint_package_skip_re <id>       ERE over a relative path: source files a
+#                                   directory count leaves out (an index module,
+#                                   a package marker, generated stubs); "" for none
+#   lint_file_length_rule <id>      "<rule> in <config file>" when a linter config
+#                                   at the repository root names a file-length
+#                                   rule outside a comment, else
+#                                   nothing. A named rule belongs to the linter:
+#                                   its limit, its counting and whether it is on
+#                                   are the repository's decision.
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
+
+lint_comment_style() {
+  case "$1" in
+    python|ruby|shell) printf 'hash' ;;
+    d)                 printf 'd' ;;
+    *)                 printf 'c' ;;
+  esac
+}
+
+lint_package_skip_re() {
+  case "$1" in
+    go)                    printf '%s' '(_gen|\.pb)\.go$' ;;
+    python)                printf '%s' '(^|/)(__init__|conftest)\.py$|_pb2(_grpc)?\.py$' ;;
+    typescript|javascript) printf '%s' '(^|/)index\.[cm]?[jt]sx?$|\.stories\.[cm]?[jt]sx?$' ;;
+  esac
+  return 0
+}
+
+# LINT_STRIP_AWK walks each line one character at a time. A quote opens a
+# string that a comment marker cannot end; single and double quotes close at
+# the end of the line, a backtick string (c and d) and a triple-quoted string
+# (hash) run on. A block comment may open after code and run on. The awk uses
+# substr and string compares only, so mawk, gawk and BSD awk read it alike.
+LINT_STRIP_AWK='
+BEGIN { bq = sprintf("%c", 96); sq = sprintf("%c", 39); dq = "\"" }
+{
+  line = $0; out = ""; n = length(line); i = 1
+  if (q == dq || q == sq) q = ""
+  while (i <= n) {
+    if (inblock) {
+      if (substr(line, i, length(closer)) == closer) { inblock = 0; i += length(closer); out = out " "; continue }
+      i++; continue
+    }
+    ch = substr(line, i, 1)
+    if (q != "") {
+      if (ch == "\\" && (q == dq || q == sq)) { out = out substr(line, i, 2); i += 2; continue }
+      if (substr(line, i, length(q)) == q) { out = out q; i += length(q); q = ""; continue }
+      out = out ch; i++; continue
+    }
+    if (style == "hash" || style == "ini") {
+      if (ch == "#") break
+      if (style == "ini" && ch == ";" && out ~ /^[ \t]*$/) break
+      three = substr(line, i, 3)
+      if (style == "hash" && (three == dq dq dq || three == sq sq sq)) { q = three; out = out three; i += 3; continue }
+    } else {
+      two = substr(line, i, 2)
+      if (two == "//") break
+      if (two == "/*" || (style == "d" && two == "/+")) { inblock = 1; closer = (two == "/+") ? "+/" : "*/"; out = out " "; i += 2; continue }
+      if (ch == bq) { q = bq; out = out ch; i++; continue }
+    }
+    if (ch == dq || ch == sq) { q = ch; out = out ch; i++; continue }
+    out = out ch; i++
+  }
+  print out
+}
+'
+
+lint_strip_comments() { # <style> <file>
+  awk -v style="$1" "$LINT_STRIP_AWK" "$2"
+}
+
+# _lint_config_style <config file> — how that config format writes a comment
+_lint_config_style() {
+  case "$1" in
+    *.yaml|*.yml|*.toml) printf 'hash' ;;
+    *.cfg|*.ini|.pylintrc|pylintrc) printf 'ini' ;;
+    *) printf 'c' ;;
+  esac
+}
+
+# _lint_names <ERE> <file>... — print the first file whose text outside its
+# comments matches the pattern
+_lint_names() {
+  local re="$1" f; shift
+  for f in "$@"; do
+    [[ -f "$f" ]] || continue
+    lint_strip_comments "$(_lint_config_style "$f")" "./$f" 2>/dev/null | grep -qE -- "$re" && { printf '%s' "$f"; return 0; }
+  done
+  return 1
+}
+
+lint_file_length_rule() {
+  local f
+  case "$1" in
+    go)
+      f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
+        && printf 'revive file-length-limit in %s' "$f" ;;
+    typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
+      local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+      if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'sonarjs/max-lines in %s' "$f"
+      elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'max-lines in %s' "$f"
+      fi ;;
+    python)
+      f=$(_lint_names '^[[:space:]]*max-module-lines[[:space:]]*=' pyproject.toml .pylintrc pylintrc setup.cfg tox.ini) \
+        && printf 'pylint max-module-lines in %s' "$f" ;;
+  esac
+  return 0
+}
+
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
+  case "$1" in
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
+  esac
+}
+# ================== end linter table ==================
+
 # ========================= cases =========================
 run_row_cases() { # runs every case against the current row
 
@@ -233,7 +412,16 @@ finish
 begin "the plugin's default names a linter setting to propose, never to add"
 write_src "src/a$FX_EXT" 1
 run_lint file-length
-expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a setting to propose, never to add on your own: " && ok
+SETUP_DIR="$(dirname "$LINT")/../setup"
+if [[ -n "$FX_SETUP_FILE" ]]; then
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" \
+    && expect_has "a setting to propose, never to add on your own: " \
+    && expect_has "$FX_LENGTH_RULE, as the plugin's setup/$FX_SETUP_FILE sets it" \
+    && { grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && grep -q -- "$MAX_LINES" "$SETUP_DIR/$FX_SETUP_FILE" || bad "setup/$FX_SETUP_FILE does not set $FX_LENGTH_RULE at $MAX_LINES"; } \
+    && grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && ok
+else
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a .ldd-lint.yaml entry file_max_lines" && ok
+fi
 finish
 
 begin "a file-length rule in the linter config hands file length to the linter"
@@ -265,6 +453,39 @@ run_lint file-length
 expect_exit 0 && expect_not "held by " && expect_has "src/over$FX_EXT: $((MAX_LINES + 1)) code lines" && ok
 finish
 
+begin "the recommended config enables every rule the routing table routes to a design rule"
+if [[ -z "$FX_ROUTED_FILE" ]]; then skip "this plugin's routing table names no linter rule"; finish
+else
+  table=$(grep -l '^| Linter failure | Route |' "$(dirname "$LINT")"/../skills/refactoring/*.md | head -1)
+  missing=""; checked=0
+  while IFS= read -r id; do
+    case " $FX_ROUTED_SKIP " in *" $id "*) continue ;; esac
+    checked=$((checked + 1))
+    case "$id" in
+      *'*') re="(^|[^A-Za-z0-9/@-])${id%\*}" ;;
+      *)    re="(^|[^A-Za-z0-9/@-])${id}([^A-Za-z0-9/-]|\$)" ;;
+    esac
+    grep -qE -- "$re" "$(dirname "$LINT")/../setup/$FX_ROUTED_FILE" || missing="$missing $id"
+  done < <(awk -F'|' '
+      /^\| Linter failure \| Route \|/ { t = 1; next }
+      t && /^\|---/ { next }
+      t && /^\|/ { if ($3 ~ /rules\/R/) { c = $2; while (match(c, /`[^`]+`/)) { print substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) } } next }
+      t { t = 0 }' "$table" | grep -E -- "$FX_RULE_ID_RE" | LC_ALL=C sort -u)
+  { [[ -n "$table" ]] && (( checked > 0 )) || bad "no routed rule id found in the routing table"; } \
+    && { [[ -z "$missing" ]] || bad "setup/$FX_ROUTED_FILE lacks:$missing"; } && [[ -z "$missing" ]] && ok
+  finish
+fi
+
+begin "the recommended fragment, kept as its own file and imported, hands file length to the linter"
+if [[ -z "$FX_ADOPTED_CONFIG" ]]; then skip "this language's setup is copied into the linter's own config"; finish
+else
+  cp "$(dirname "$LINT")/../setup/$FX_ADOPTED_CONFIG" "$REPO/$FX_ADOPTED_CONFIG"
+  write_src "src/over$FX_EXT" $((MAX_LINES + 50))
+  run_lint file-length
+  expect_exit 0 && expect_has "held by " && expect_has "in $FX_ADOPTED_CONFIG" && expect_no_finding && ok
+  finish
+fi
+
 begin ".ldd-lint.yaml sets the limit when the linter holds none"
 printf 'file_max_lines: 100  # this repository\n' > "$REPO/.ldd-lint.yaml"
 write_src "src/a$FX_EXT" 101
@@ -403,6 +624,18 @@ for opt in --root --files --glob --test-re; do
   finish
 done
 
+# --- the recommended configs under setup/, checked by their own linters when
+# the machine has them ---
+SETUP_DIR="$(dirname "$LINT")/../setup"
+
+while IFS=$'\t' read -r setup_file setup_tool; do
+  begin "setup/$setup_file passes its own linter's check"
+  if ! command -v "$setup_tool" >/dev/null 2>&1; then skip "$setup_tool is not on PATH"; finish; continue; fi
+  OUT=$(lint_setup_check "$setup_file" "$SETUP_DIR" "$REPO" 2>&1); CODE=$?; ERR=""
+  expect_exit 0 && ok
+  finish
+done < <(lint_setup_files)
+
 # ========================= summary =========================
 echo
 echo "ldd-lint_test: $pass passed, $failed failed, $skipped skipped"
diff --git a/python-linter-driven-development/scripts/ldd-scope_test.sh b/python-linter-driven-development/scripts/ldd-scope_test.sh
index c3c837f..fbd7a47 100755
--- a/python-linter-driven-development/scripts/ldd-scope_test.sh
+++ b/python-linter-driven-development/scripts/ldd-scope_test.sh
@@ -117,6 +117,18 @@ mk_repo() { fx_write_marker "$REPO" fixture; fx_write_code; mk_docs; }
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -132,6 +144,12 @@ FX_NATIVE="python"
 
 use_row() {
   FX_LINTER_CONFIG='pyproject.toml'
+  FX_SETUP_FILE=''
+  FX_ADOPTED_CONFIG=''
+  FX_ROUTED_FILE='ruff.toml'
+  FX_RULE_ID_RE='^[A-Z]+[0-9]+$'
+  FX_ROUTED_SKIP=''
+  FX_LENGTH_RULE=''
   FX_LINTER_COMMENT='#'
   FX_EXT='.py'
   FX_LINE_COMMENT='# note'
diff --git a/python-linter-driven-development/setup/eslint.config.ldd.mjs b/python-linter-driven-development/setup/eslint.config.ldd.mjs
new file mode 100644
index 0000000..85da438
--- /dev/null
+++ b/python-linter-driven-development/setup/eslint.config.ldd.mjs
@@ -0,0 +1,115 @@
+// Recommended ESLint flat-config fragment of the linter-driven-development
+// plugins: every rule the plugin's routing table routes to one of the twelve
+// design rules, at the limits the rules name. Each rule line says which rule its
+// failures feed. The plugin never writes this file into a repository: the
+// repository's owners copy it, or the parts they want, beside eslint.config.js
+// and spread it before their own entries. Later entries win, so every limit the
+// repository's config already sets stays the repository's:
+//
+//   import ldd from './eslint.config.ldd.mjs'
+//   export default [...ldd, ...yourConfig]
+//
+// residue-exempt: an ESLint configuration names its plugins and rules on purpose.
+// It needs eslint-plugin-sonarjs, eslint-plugin-react, eslint-plugin-react-hooks,
+// eslint-plugin-promise, eslint-plugin-import and typescript-eslint; a repository
+// that does not use one of them leaves its rules out. The @typescript-eslint rules
+// below need type information: the repository's config sets typescript-eslint's
+// parser with parserOptions.projectService for these files, or ESLint stops with
+// an error. Limits a repository already sets stay the repository's: the linter is
+// the authority for every threshold it holds. Rules this file leaves out (style,
+// imports, formatting) are the repository's own choice, and so is
+// no-restricted-syntax on import.meta.env outside the config module (R8): the
+// config module's path is the repository's.
+//
+// Adopt it on an existing codebase with ESLint's bulk suppressions: run
+// `npx eslint --suppress-all` once to record today's violations, so only new ones
+// fail; `npx eslint --prune-suppressions` drops the entries that are fixed.
+
+import importPlugin from 'eslint-plugin-import'
+import promise from 'eslint-plugin-promise'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import sonarjs from 'eslint-plugin-sonarjs'
+import tseslint from 'typescript-eslint'
+
+export default [
+  {
+    files: ['**/*.{ts,tsx}'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+      import: importPlugin,
+      promise,
+      react,
+      'react-hooks': reactHooks,
+      sonarjs,
+    },
+    rules: {
+      // R3 storifying
+      'sonarjs/cognitive-complexity': ['error', 15],
+      'sonarjs/cyclomatic-complexity': ['error', { threshold: 10 }],
+      'sonarjs/expression-complexity': ['error', { max: 5 }],
+      // R3's limits: more than 50 lines or more than 2 nesting levels
+      'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],
+      'sonarjs/nested-control-flow': ['error', { maximumNestingLevel: 2 }],
+      'sonarjs/no-nested-conditional': 'error',
+      'sonarjs/no-nested-functions': 'error',
+      'sonarjs/elseif-without-else': 'error',
+      'react/no-unstable-nested-components': 'error',
+      // R1 primitive obsession
+      'max-params': ['error', 4],
+      'sonarjs/no-duplicate-string': ['error', { threshold: 3 }],
+      'sonarjs/max-union-size': ['error', { threshold: 4 }],
+      'sonarjs/no-identical-functions': 'error',
+      'react/no-array-index-key': 'error',
+      'no-magic-numbers': ['error', {
+        ignore: [-1, 0, 1, 2],
+        ignoreArrayIndexes: true,
+        ignoreDefaultValues: true,
+        ignoreClassFieldInitialValues: true,
+        detectObjects: false,
+      }],
+      // R2 self-validating types: parse at the boundary
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'error',
+      '@typescript-eslint/no-unsafe-assignment': 'error',
+      '@typescript-eslint/no-unsafe-call': 'error',
+      '@typescript-eslint/no-unsafe-member-access': 'error',
+      '@typescript-eslint/no-unsafe-return': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'error',
+      // R5 vertical slice: one juicy module per file; counts code lines only
+      'sonarjs/max-lines': ['error', { maximum: 450 }],
+      'react/no-multi-comp': ['error', { ignoreStateless: false }],
+      // R8 no globals
+      'import/no-mutable-exports': 'error',
+      // R10 concurrency safety
+      'react-hooks/exhaustive-deps': 'error',
+      'react-hooks/set-state-in-effect': 'error',
+      '@typescript-eslint/no-floating-promises': 'error',
+      '@typescript-eslint/no-misused-promises': 'error',
+      'promise/catch-or-return': 'error',
+      // R11 conditional dispatch
+      '@typescript-eslint/switch-exhaustiveness-check': 'error',
+      'sonarjs/no-nested-switch': 'error',
+      'sonarjs/max-switch-cases': 'error',
+      'sonarjs/no-small-switch': 'error',
+      // R12 mutation discipline
+      'no-param-reassign': ['error', { props: true }],
+      'sonarjs/prefer-read-only-props': 'error',
+      'react/no-direct-mutation-state': 'error',
+    },
+  },
+  {
+    // Tests are long and repeat literals by design.
+    files: ['**/*.test.{ts,tsx}', '**/*.spec.{ts,tsx}'],
+    rules: {
+      'sonarjs/max-lines-per-function': 'off',
+      'sonarjs/no-duplicate-string': 'off',
+      'sonarjs/no-nested-functions': 'off',
+      'max-params': 'off',
+      'no-magic-numbers': 'off',
+      'react/no-multi-comp': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+]
diff --git a/python-linter-driven-development/setup/golangci.yaml b/python-linter-driven-development/setup/golangci.yaml
new file mode 100644
index 0000000..fd73147
--- /dev/null
+++ b/python-linter-driven-development/setup/golangci.yaml
@@ -0,0 +1,86 @@
+# Recommended golangci-lint v2 configuration of the linter-driven-development
+# plugins: every linter rule the plugin's routing table routes to one of the
+# twelve design rules, at the limits the rules name. Each linter line says which
+# rule its failures feed. The plugin never writes this file into a repository:
+# the repository's owners copy it, or the parts they want, into .golangci.yaml.
+# residue-exempt: a golangci-lint configuration names its linters on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# naming, formatting) are the repository's own choice.
+#
+# Adopt it on an existing codebase with the ratchet below: only issues in code
+# changed since the merge base with main fail, so old code is not a wall of
+# findings on day one. CI needs main in the clone for it (fetch-depth: 0 in
+# GitHub Actions). Remove the ratchet once the old findings are gone.
+# gocyclo stands for the routing table's "gocyclo / cyclop": enable one of the two.
+
+version: "2"
+
+issues:
+  new-from-merge-base: main
+
+linters:
+  # The standard set (errcheck, govet, ineffassign, staticcheck, unused) stays on;
+  # the linters below are added to it.
+  default: standard
+  enable:
+    - gocyclo           # R3 storifying: cyclomatic complexity
+    - gocognit          # R3 storifying: cognitive complexity
+    - funlen            # R3 storifying: function length
+    - nestif            # R3 storifying: nesting depth
+    - maintidx          # R3 storifying, R1 types: maintainability index
+    - dupl              # R1 types: duplicated logic; a duplicated switch is R11
+    - exhaustive        # R11 conditional dispatch: missing enum cases
+    - gochecknoglobals  # R8 no globals
+    - gochecknoinits    # R8 no globals
+    - ireturn           # R6 test-only interfaces: a constructor that returns an interface
+    - govet             # R10 concurrency: copylocks
+    - revive            # R1 types, R5 vertical slice: the rules below
+    - errcheck          # mechanical: an error that is not handled
+    - wrapcheck         # mechanical: an error without the context of its layer
+    - goconst           # mechanical; an enum-shaped string is R1's "Name enum strings"
+  settings:
+    gocyclo:
+      min-complexity: 10
+    gocognit:
+      min-complexity: 15
+    funlen:
+      lines: 50
+      statements: 40
+    nestif:
+      min-complexity: 2
+    maintidx:
+      under: 20
+    dupl:
+      threshold: 100
+    exhaustive:
+      # A default branch does not count as handling a case: every new case is
+      # handled where the switch is.
+      default-signifies-exhaustive: false
+    govet:
+      enable:
+        - copylocks
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    revive:
+      rules:
+        - name: argument-limit          # R1: more than 4 parameters wants a parameter object
+          arguments: [4]
+        - name: function-result-limit   # R1: more than 3 results wants a named result type
+          arguments: [3]
+        - name: file-length-limit       # R5: one juicy type per file; counts code lines only
+          arguments: [{max: 450, skip-comments: true, skip-blank-lines: true}]
+        - name: early-return            # mechanical: invert the condition and return early
+  exclusions:
+    rules:
+      # Tests are long and repeat literals by design.
+      - path: _test\.go
+        linters:
+          - funlen
+          - gocognit
+          - gocyclo
+          - maintidx
+          - dupl
+          - goconst
diff --git a/python-linter-driven-development/setup/ruff.toml b/python-linter-driven-development/setup/ruff.toml
new file mode 100644
index 0000000..03571ca
--- /dev/null
+++ b/python-linter-driven-development/setup/ruff.toml
@@ -0,0 +1,58 @@
+# Recommended ruff configuration of the linter-driven-development plugins:
+# every rule the plugin's routing table routes to one of the twelve design
+# rules, at the limits the rules name. Each rule says which rule its failures
+# feed. The plugin never writes this file into a repository: the repository's
+# owners copy it, or the parts they want, into ruff.toml, or into
+# pyproject.toml with each table name prefixed by "tool.ruff." ([lint] becomes
+# [tool.ruff.lint]).
+# residue-exempt: a ruff configuration names its rule codes on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# docstrings, imports) are the repository's own choice. ruff has no file-length
+# rule: the plugin's gap linter, scripts/ldd-lint.sh file-length, holds that
+# limit at 450 code lines.
+#
+# Adopt it on an existing codebase one change at a time: run ruff on the files
+# changed since the merge base with main, so old code is not a wall of
+# findings on day one:
+#   git diff -z --name-only --diff-filter=d "$(git merge-base HEAD main)" -- '*.py' \
+#     | xargs -0 sh -c '[ "$#" -eq 0 ] || ruff check "$@"' sh
+# The sh guard keeps an empty change list from checking the whole repository,
+# and -z with -0 keeps a path with spaces whole.
+
+[lint]
+# PLR1702 (nested blocks) is a preview rule. Preview mode also turns on preview
+# behavior of the stable rules a repository already selects; a repository that
+# does not want that drops these two lines and PLR1702.
+preview = true
+explicit-preview-rules = true
+extend-select = [
+  "C901",     # R3 storifying: complexity
+  "PLR0911",  # R3 storifying: too many returns
+  "PLR0912",  # R3 storifying: too many branches
+  "PLR0915",  # R3 storifying: too many statements
+  "PLR1702",  # R3 storifying: nesting
+  "PLR0913",  # R1 types: too many arguments wants a parameter object
+  "PLR2004",  # R1 types: a magic value; an enum-shaped string is "Name enum strings"
+  "FBT001",   # R11 conditional dispatch: a boolean positional parameter
+  "FBT002",   # R11 conditional dispatch: a boolean default parameter
+  "PLW0603",  # R8 no globals: a global statement
+  "B006",     # R12 mutation discipline: a mutable default argument
+  "B008",     # R12 mutation discipline: a call in a default argument
+]
+
+[lint.mccabe]
+max-complexity = 8
+
+[lint.pylint]
+max-args = 4          # self and cls are not counted
+max-branches = 12
+max-returns = 6
+max-statements = 50
+max-nested-blocks = 2  # R3: more than 2 nesting levels
+
+[lint.per-file-ignores]
+# Tests repeat literals and take many fixtures by design.
+"**/test_*.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
+"**/*_test.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
diff --git a/ts-react-linter-driven-development/CHANGELOG.md b/ts-react-linter-driven-development/CHANGELOG.md
index d4d78ed..a452a3a 100644
--- a/ts-react-linter-driven-development/CHANGELOG.md
+++ b/ts-react-linter-driven-development/CHANGELOG.md
@@ -7,6 +7,15 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Added
 
+- **A recommended linter setup.** `setup/golangci.yaml`, `setup/ruff.toml` and
+  `setup/eslint.config.ldd.mjs` enable every linter rule the routing table routes to
+  a design rule, at the limits the rules name, with a way to adopt each on an
+  existing codebase: golangci-lint's merge-base ratchet, ESLint's bulk
+  suppressions, and ruff on changed files. The plugin never writes them into a
+  repository. The gap linter's threshold line names the file and rule that would
+  hold a file-length limit; for Python, where ruff has no file-length rule, it says
+  that the gap linter holds it.
+
 - **A gap linter for the design triggers no linter holds.** `scripts/ldd-lint.sh`
   measures lines per source file (`file-length`) and source files per directory
   (`package-size`). Where the repository's linter config names a file-length rule,
@@ -27,6 +36,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versio
 
 ### Fixed
 
+- **The gap linter runs under bash 3.2.** macOS's `/bin/bash` stopped
+  `ldd-lint.sh` with a syntax error: bash 3.2 misreads a `case` pattern inside a
+  process substitution. The script now runs under bash 3.2 and bash 5.
+
 - **A value-taking option given last no longer hangs the review scripts.** When
   `ldd-detect.sh` or `ldd-scope.sh` got an option such as `--root` or `--base` as
   its last argument, the script looped forever. It now stops with "<option> needs
diff --git a/ts-react-linter-driven-development/README.md b/ts-react-linter-driven-development/README.md
index a0498f2..3117d92 100644
--- a/ts-react-linter-driven-development/README.md
+++ b/ts-react-linter-driven-development/README.md
@@ -142,6 +142,12 @@ adds a checker the repository does not use.
   `@ts-expect-error`, `@ts-ignore`, `@ts-nocheck` and `// prettier-ignore`. The
   lint-fixer never adds one and never edits `eslint.config.*`, `tsconfig*.json` or
   `.prettierrc*`; a new one in a diff is itself a review finding.
+- **The recommended setup makes the design triggers fire.** `setup/eslint.config.ldd.mjs`
+  in the plugin directory is a flat-config fragment with every rule the routing
+  table routes to a design rule, at the limits the rules name. The plugin never
+  writes it into your repository: copy it beside `eslint.config.js` and spread it
+  before your own entries, so every limit your configuration already sets stays
+  yours.
 - **What it does not review.** Accessibility beyond what `jsx-a11y` flags —
   contrast, heading order, focus management, live regions — is the repository's
   axe run, which this plugin does not replace. Error-boundary placement and
diff --git a/ts-react-linter-driven-development/scripts/ldd-detect_test.sh b/ts-react-linter-driven-development/scripts/ldd-detect_test.sh
index a4aa109..10b19c4 100644
--- a/ts-react-linter-driven-development/scripts/ldd-detect_test.sh
+++ b/ts-react-linter-driven-development/scripts/ldd-detect_test.sh
@@ -141,6 +141,18 @@ questions_in_rules() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -159,6 +171,14 @@ FX_NATIVE="typescript"
 # Every file the row writes is a `.ts` file, so both globs select the same set.
 use_row() {
   FX_LINTER_CONFIG='eslint.config.mjs'
+  FX_SETUP_FILE='eslint.config.ldd.mjs'
+  FX_ADOPTED_CONFIG='eslint.config.ldd.mjs'
+  FX_ROUTED_FILE='eslint.config.ldd.mjs'
+  FX_RULE_ID_RE='^(@[a-z-]+/)?[a-z-]+(/[a-z*-]+)?$'
+  # no-restricted-syntax needs the repository's config module path;
+  # package-size is the gap linter's
+  FX_ROUTED_SKIP='no-restricted-syntax package-size'
+  FX_LENGTH_RULE='sonarjs/max-lines'
   FX_LINTER_COMMENT='//'
   FX_EXT='.ts'
   FX_LINE_COMMENT='// note'
diff --git a/ts-react-linter-driven-development/scripts/ldd-lint.sh b/ts-react-linter-driven-development/scripts/ldd-lint.sh
index 9d83359..54c6952 100755
--- a/ts-react-linter-driven-development/scripts/ldd-lint.sh
+++ b/ts-react-linter-driven-development/scripts/ldd-lint.sh
@@ -235,9 +235,15 @@ lang_is_test() {
 #                                   nothing. A named rule belongs to the linter:
 #                                   its limit, its counting and whether it is on
 #                                   are the repository's decision.
-#   lint_file_length_snippet <id> <max>  the linter setting that would hold the
-#                                   limit, or the .ldd-lint.yaml entry when no
-#                                   linter rule is known: text to propose
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
 
 lint_comment_style() {
   case "$1" in
@@ -326,8 +332,10 @@ lint_file_length_rule() {
       f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
         && printf 'revive file-length-limit in %s' "$f" ;;
     typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
       local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
-                     .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
       if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
         printf 'sonarjs/max-lines in %s' "$f"
       elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
@@ -340,12 +348,27 @@ lint_file_length_rule() {
   return 0
 }
 
-lint_file_length_snippet() {
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
   case "$1" in
-    go)                    printf "revive in .golangci.yaml: - name: file-length-limit, arguments: [{max: %s, skip-comments: true, skip-blank-lines: true}]" "$2" ;;
-    typescript|javascript) printf "the eslint config: 'sonarjs/max-lines': ['error', { maximum: %s }]" "$2" ;;
-    python)                printf "pyproject.toml: [tool.pylint.format] max-module-lines = %s (pylint counts every line, comments and blank lines too)" "$2" ;;
-    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: %s would state this limit" "$1" "$2" ;;
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
   esac
 }
 # ================== end linter table ==================
@@ -417,6 +440,16 @@ trap 'rm -f "$SCOPE" "$INVENTORY"' EXIT
 list_candidates | by_language > "$SCOPE"
 if [[ -n "$FILES_LIST" ]]; then list_repo | by_language > "$INVENTORY"; else cp "$SCOPE" "$INVENTORY"; fi
 
+# dir_of <path> — the directory part of a relative path, "." for a file at
+# the root. A function, because bash 3.2 misreads a case pattern's ")" inside
+# a process substitution.
+dir_of() {
+  case "$1" in
+    */*) printf '%s\n' "${1%/*}" ;;
+    *)   printf '.\n' ;;
+  esac
+}
+
 # measured <path> — exit 0 when the file counts for this language: not under
 # an excluded directory, not a test, not generated. Every path the script
 # hands to find, head or awk starts with "./", and a directory is cut from a
@@ -448,7 +481,7 @@ run_file_length() { # <id> — every measured file of that language
     say "threshold: $id file length — set by $OVERRIDE_FILE ($max code lines)"
   else
     max="$DEFAULT_FILE_MAX_LINES"; src="profile default"
-    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; a setting to propose, never to add on your own: $(lint_file_length_snippet "$id" "$max")"
+    say "threshold: $id file length — profile default ($max code lines); the repository's linter does not hold it; $(lint_file_length_proposal "$id")"
   fi
   while IFS=$'\t' read -r _ f; do
     measured "$f" || continue
@@ -472,7 +505,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
   awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$INVENTORY" | while IFS= read -r f; do
     [[ -n "$skip" ]] && printf '%s\n' "$f" | grep -qE -- "$skip" && continue
     measured "$f" || continue
-    case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+    dir_of "$f"
   done | LC_ALL=C sort | uniq -c | awk '{ n = $1; sub(/^[ \t]*[0-9]+[ \t]/, ""); print $0 "\t" n }' > "$counts"
   while IFS= read -r d; do
     n=$(awk -F'\t' -v d="$d" '$1 == d { print $2; exit }' "$counts")
@@ -483,8 +516,7 @@ run_package_size() { # <id> — every directory that holds a measured file of th
       finding "$d" "$n source files (warning at $warn, $src)"
     fi
   done < <(awk -F'\t' -v id="$id" '$1 == id { print $2 }' "$SCOPE" | while IFS= read -r f; do
-             measured "$f" || continue
-             case "$f" in */*) printf '%s\n' "${f%/*}" ;; *) printf '.\n' ;; esac
+             measured "$f" && dir_of "$f"
            done | LC_ALL=C sort -u)
   rm -f "$counts"
 }
diff --git a/ts-react-linter-driven-development/scripts/ldd-lint_test.sh b/ts-react-linter-driven-development/scripts/ldd-lint_test.sh
index 4a85f8c..cfec7bf 100644
--- a/ts-react-linter-driven-development/scripts/ldd-lint_test.sh
+++ b/ts-react-linter-driven-development/scripts/ldd-lint_test.sh
@@ -105,6 +105,18 @@ fill_dir() {
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -123,6 +135,14 @@ FX_NATIVE="typescript"
 # Every file the row writes is a `.ts` file, so both globs select the same set.
 use_row() {
   FX_LINTER_CONFIG='eslint.config.mjs'
+  FX_SETUP_FILE='eslint.config.ldd.mjs'
+  FX_ADOPTED_CONFIG='eslint.config.ldd.mjs'
+  FX_ROUTED_FILE='eslint.config.ldd.mjs'
+  FX_RULE_ID_RE='^(@[a-z-]+/)?[a-z-]+(/[a-z*-]+)?$'
+  # no-restricted-syntax needs the repository's config module path;
+  # package-size is the gap linter's
+  FX_ROUTED_SKIP='no-restricted-syntax package-size'
+  FX_LENGTH_RULE='sonarjs/max-lines'
   FX_LINTER_COMMENT='//'
   FX_EXT='.ts'
   FX_LINE_COMMENT='// note'
@@ -178,6 +198,167 @@ fx_write_linter_config_other() {
   printf "export default [{\n  rules: {\n    'max-lines-per-function': ['error', 50],\n    'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],\n  },\n}]\n" > "$REPO/eslint.config.mjs"
 }
 
+# ==================== linter table ====================
+# What the gap linter needs to know per language id: how a comment is written,
+# which source files a directory count leaves out, and whether the
+# repository's own linter holds the file-length limit. The same table is
+# rendered into every plugin, so two plugins measure one file the same way.
+# residue-exempt: the table names every language's linter and config file on
+# purpose, the same in every rendering.
+#
+#   lint_comment_style <id>         c (// and /* */), d (also /+ +/) or hash (#)
+#   lint_strip_comments <style> <file>  the file with every comment removed and
+#                                   string literals kept, one output line per
+#                                   input line: a comment-only line prints empty.
+#                                   Styles: c, d, hash (# and triple-quoted
+#                                   strings), ini (# and a leading ;)
+#   lint_package_skip_re <id>       ERE over a relative path: source files a
+#                                   directory count leaves out (an index module,
+#                                   a package marker, generated stubs); "" for none
+#   lint_file_length_rule <id>      "<rule> in <config file>" when a linter config
+#                                   at the repository root names a file-length
+#                                   rule outside a comment, else
+#                                   nothing. A named rule belongs to the linter:
+#                                   its limit, its counting and whether it is on
+#                                   are the repository's decision.
+#   lint_setup_files                one line per recommended config under the
+#                                   plugin's setup/: file TAB the tool that checks it
+#   lint_setup_check <file> <setup dir> <work dir>  run that tool's own check of
+#                                   the file; exit 0 when the tool accepts it
+#   lint_file_length_proposal <id>  what would hold the limit in the
+#                                   repository's linter: the rule, named after
+#                                   the plugin's recommended config under setup/
+#                                   that sets it, or the .ldd-lint.yaml entry when
+#                                   the language's linter has no such rule
+
+lint_comment_style() {
+  case "$1" in
+    python|ruby|shell) printf 'hash' ;;
+    d)                 printf 'd' ;;
+    *)                 printf 'c' ;;
+  esac
+}
+
+lint_package_skip_re() {
+  case "$1" in
+    go)                    printf '%s' '(_gen|\.pb)\.go$' ;;
+    python)                printf '%s' '(^|/)(__init__|conftest)\.py$|_pb2(_grpc)?\.py$' ;;
+    typescript|javascript) printf '%s' '(^|/)index\.[cm]?[jt]sx?$|\.stories\.[cm]?[jt]sx?$' ;;
+  esac
+  return 0
+}
+
+# LINT_STRIP_AWK walks each line one character at a time. A quote opens a
+# string that a comment marker cannot end; single and double quotes close at
+# the end of the line, a backtick string (c and d) and a triple-quoted string
+# (hash) run on. A block comment may open after code and run on. The awk uses
+# substr and string compares only, so mawk, gawk and BSD awk read it alike.
+LINT_STRIP_AWK='
+BEGIN { bq = sprintf("%c", 96); sq = sprintf("%c", 39); dq = "\"" }
+{
+  line = $0; out = ""; n = length(line); i = 1
+  if (q == dq || q == sq) q = ""
+  while (i <= n) {
+    if (inblock) {
+      if (substr(line, i, length(closer)) == closer) { inblock = 0; i += length(closer); out = out " "; continue }
+      i++; continue
+    }
+    ch = substr(line, i, 1)
+    if (q != "") {
+      if (ch == "\\" && (q == dq || q == sq)) { out = out substr(line, i, 2); i += 2; continue }
+      if (substr(line, i, length(q)) == q) { out = out q; i += length(q); q = ""; continue }
+      out = out ch; i++; continue
+    }
+    if (style == "hash" || style == "ini") {
+      if (ch == "#") break
+      if (style == "ini" && ch == ";" && out ~ /^[ \t]*$/) break
+      three = substr(line, i, 3)
+      if (style == "hash" && (three == dq dq dq || three == sq sq sq)) { q = three; out = out three; i += 3; continue }
+    } else {
+      two = substr(line, i, 2)
+      if (two == "//") break
+      if (two == "/*" || (style == "d" && two == "/+")) { inblock = 1; closer = (two == "/+") ? "+/" : "*/"; out = out " "; i += 2; continue }
+      if (ch == bq) { q = bq; out = out ch; i++; continue }
+    }
+    if (ch == dq || ch == sq) { q = ch; out = out ch; i++; continue }
+    out = out ch; i++
+  }
+  print out
+}
+'
+
+lint_strip_comments() { # <style> <file>
+  awk -v style="$1" "$LINT_STRIP_AWK" "$2"
+}
+
+# _lint_config_style <config file> — how that config format writes a comment
+_lint_config_style() {
+  case "$1" in
+    *.yaml|*.yml|*.toml) printf 'hash' ;;
+    *.cfg|*.ini|.pylintrc|pylintrc) printf 'ini' ;;
+    *) printf 'c' ;;
+  esac
+}
+
+# _lint_names <ERE> <file>... — print the first file whose text outside its
+# comments matches the pattern
+_lint_names() {
+  local re="$1" f; shift
+  for f in "$@"; do
+    [[ -f "$f" ]] || continue
+    lint_strip_comments "$(_lint_config_style "$f")" "./$f" 2>/dev/null | grep -qE -- "$re" && { printf '%s' "$f"; return 0; }
+  done
+  return 1
+}
+
+lint_file_length_rule() {
+  local f
+  case "$1" in
+    go)
+      f=$(_lint_names 'file-length-limit' .golangci.yaml .golangci.yml .golangci.toml .golangci.json) \
+        && printf 'revive file-length-limit in %s' "$f" ;;
+    typescript|javascript)
+      # eslint.config.ldd.mjs is the plugin's recommended fragment: a repository
+      # that adopts it keeps it beside eslint.config.js and imports it.
+      local configs=(eslint.config.js eslint.config.mjs eslint.config.cjs eslint.config.ts eslint.config.mts eslint.config.cts
+                     eslint.config.ldd.mjs .eslintrc .eslintrc.js .eslintrc.cjs .eslintrc.json .eslintrc.yml .eslintrc.yaml)
+      if f=$(_lint_names 'sonarjs/max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'sonarjs/max-lines in %s' "$f"
+      elif f=$(_lint_names '(^|[^-/a-zA-Z])max-lines([^-a-zA-Z]|$)' "${configs[@]}"); then
+        printf 'max-lines in %s' "$f"
+      fi ;;
+    python)
+      f=$(_lint_names '^[[:space:]]*max-module-lines[[:space:]]*=' pyproject.toml .pylintrc pylintrc setup.cfg tox.ini) \
+        && printf 'pylint max-module-lines in %s' "$f" ;;
+  esac
+  return 0
+}
+
+lint_setup_files() {
+  printf 'golangci.yaml\tgolangci-lint\n'
+  printf 'ruff.toml\truff\n'
+  printf 'eslint.config.ldd.mjs\tnode\n'
+}
+
+lint_setup_check() { # <file> <setup dir> <work dir>
+  case "$1" in
+    golangci.yaml)         golangci-lint config verify -c "$2/$1" ;;
+    ruff.toml)             printf 'x = 1\n' > "$3/ldd_setup_check.py" && (cd "$3" && ruff check --no-cache --config "$2/$1" ldd_setup_check.py) ;;
+    eslint.config.ldd.mjs) node --check "$2/$1" ;;
+    *)                     return 2 ;;
+  esac
+}
+
+lint_file_length_proposal() {
+  case "$1" in
+    go)                    printf "a setting to propose, never to add on your own: revive file-length-limit, as the plugin's setup/golangci.yaml sets it" ;;
+    typescript|javascript) printf "a setting to propose, never to add on your own: sonarjs/max-lines, as the plugin's setup/eslint.config.ldd.mjs sets it" ;;
+    python)                printf "ruff has no file-length rule, so this script holds the limit; a .ldd-lint.yaml entry file_max_lines: <n> states another" ;;
+    *)                     printf "no linter rule is known for %s; a .ldd-lint.yaml entry file_max_lines: <n> states another limit" "$1" ;;
+  esac
+}
+# ================== end linter table ==================
+
 # ========================= cases =========================
 run_row_cases() { # runs every case against the current row
 
@@ -237,7 +418,16 @@ finish
 begin "the plugin's default names a linter setting to propose, never to add"
 write_src "src/a$FX_EXT" 1
 run_lint file-length
-expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a setting to propose, never to add on your own: " && ok
+SETUP_DIR="$(dirname "$LINT")/../setup"
+if [[ -n "$FX_SETUP_FILE" ]]; then
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" \
+    && expect_has "a setting to propose, never to add on your own: " \
+    && expect_has "$FX_LENGTH_RULE, as the plugin's setup/$FX_SETUP_FILE sets it" \
+    && { grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && grep -q -- "$MAX_LINES" "$SETUP_DIR/$FX_SETUP_FILE" || bad "setup/$FX_SETUP_FILE does not set $FX_LENGTH_RULE at $MAX_LINES"; } \
+    && grep -q -- "$FX_LENGTH_RULE" "$SETUP_DIR/$FX_SETUP_FILE" && ok
+else
+  expect_exit 0 && expect_has "profile default ($MAX_LINES code lines)" && expect_has "a .ldd-lint.yaml entry file_max_lines" && ok
+fi
 finish
 
 begin "a file-length rule in the linter config hands file length to the linter"
@@ -269,6 +459,39 @@ run_lint file-length
 expect_exit 0 && expect_not "held by " && expect_has "src/over$FX_EXT: $((MAX_LINES + 1)) code lines" && ok
 finish
 
+begin "the recommended config enables every rule the routing table routes to a design rule"
+if [[ -z "$FX_ROUTED_FILE" ]]; then skip "this plugin's routing table names no linter rule"; finish
+else
+  table=$(grep -l '^| Linter failure | Route |' "$(dirname "$LINT")"/../skills/refactoring/*.md | head -1)
+  missing=""; checked=0
+  while IFS= read -r id; do
+    case " $FX_ROUTED_SKIP " in *" $id "*) continue ;; esac
+    checked=$((checked + 1))
+    case "$id" in
+      *'*') re="(^|[^A-Za-z0-9/@-])${id%\*}" ;;
+      *)    re="(^|[^A-Za-z0-9/@-])${id}([^A-Za-z0-9/-]|\$)" ;;
+    esac
+    grep -qE -- "$re" "$(dirname "$LINT")/../setup/$FX_ROUTED_FILE" || missing="$missing $id"
+  done < <(awk -F'|' '
+      /^\| Linter failure \| Route \|/ { t = 1; next }
+      t && /^\|---/ { next }
+      t && /^\|/ { if ($3 ~ /rules\/R/) { c = $2; while (match(c, /`[^`]+`/)) { print substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) } } next }
+      t { t = 0 }' "$table" | grep -E -- "$FX_RULE_ID_RE" | LC_ALL=C sort -u)
+  { [[ -n "$table" ]] && (( checked > 0 )) || bad "no routed rule id found in the routing table"; } \
+    && { [[ -z "$missing" ]] || bad "setup/$FX_ROUTED_FILE lacks:$missing"; } && [[ -z "$missing" ]] && ok
+  finish
+fi
+
+begin "the recommended fragment, kept as its own file and imported, hands file length to the linter"
+if [[ -z "$FX_ADOPTED_CONFIG" ]]; then skip "this language's setup is copied into the linter's own config"; finish
+else
+  cp "$(dirname "$LINT")/../setup/$FX_ADOPTED_CONFIG" "$REPO/$FX_ADOPTED_CONFIG"
+  write_src "src/over$FX_EXT" $((MAX_LINES + 50))
+  run_lint file-length
+  expect_exit 0 && expect_has "held by " && expect_has "in $FX_ADOPTED_CONFIG" && expect_no_finding && ok
+  finish
+fi
+
 begin ".ldd-lint.yaml sets the limit when the linter holds none"
 printf 'file_max_lines: 100  # this repository\n' > "$REPO/.ldd-lint.yaml"
 write_src "src/a$FX_EXT" 101
@@ -407,6 +630,18 @@ for opt in --root --files --glob --test-re; do
   finish
 done
 
+# --- the recommended configs under setup/, checked by their own linters when
+# the machine has them ---
+SETUP_DIR="$(dirname "$LINT")/../setup"
+
+while IFS=$'\t' read -r setup_file setup_tool; do
+  begin "setup/$setup_file passes its own linter's check"
+  if ! command -v "$setup_tool" >/dev/null 2>&1; then skip "$setup_tool is not on PATH"; finish; continue; fi
+  OUT=$(lint_setup_check "$setup_file" "$SETUP_DIR" "$REPO" 2>&1); CODE=$?; ERR=""
+  expect_exit 0 && ok
+  finish
+done < <(lint_setup_files)
+
 # ========================= summary =========================
 echo
 echo "ldd-lint_test: $pass passed, $failed failed, $skipped skipped"
diff --git a/ts-react-linter-driven-development/scripts/ldd-scope_test.sh b/ts-react-linter-driven-development/scripts/ldd-scope_test.sh
index 560308a..76464f4 100755
--- a/ts-react-linter-driven-development/scripts/ldd-scope_test.sh
+++ b/ts-react-linter-driven-development/scripts/ldd-scope_test.sh
@@ -117,6 +117,18 @@ mk_repo() { fx_write_marker "$REPO" fixture; fx_write_code; mk_docs; }
 #   FX_BLOCK_OPEN      the line that opens a block comment, "" when the
 #   FX_BLOCK_CLOSE     language has none, and the line that closes it
 #   FX_SKIP_FILES      source file names a directory count leaves out
+#   FX_ROUTED_FILE     the plugin's recommended config under setup/ for the
+#                      language, which enables every rule id the refactoring
+#                      routing table routes to a design rule; FX_RULE_ID_RE the
+#                      shape of the language's rule ids in that table, and
+#                      FX_ROUTED_SKIP the ids the config leaves out on purpose;
+#                      all "" when the plugin's table names no linter rule
+#   FX_ADOPTED_CONFIG  the name under which a repository keeps the plugin's
+#                      recommended config as its own file and imports it; ""
+#                      when the setup is copied into the linter's own config
+#   FX_SETUP_FILE      the plugin's recommended config under setup/ that holds
+#                      the file-length limit, and FX_LENGTH_RULE its rule; both
+#                      "" when the language's linter has no file-length rule
 #   fx_test_file <dir> <n>             a test file's path in <dir>
 #   FX_LINTER_CONFIG   the path, under the repository root, of the file that
 #                      fx_write_linter_config writes, and FX_LINTER_COMMENT the
@@ -135,6 +147,14 @@ FX_NATIVE="typescript"
 # Every file the row writes is a `.ts` file, so both globs select the same set.
 use_row() {
   FX_LINTER_CONFIG='eslint.config.mjs'
+  FX_SETUP_FILE='eslint.config.ldd.mjs'
+  FX_ADOPTED_CONFIG='eslint.config.ldd.mjs'
+  FX_ROUTED_FILE='eslint.config.ldd.mjs'
+  FX_RULE_ID_RE='^(@[a-z-]+/)?[a-z-]+(/[a-z*-]+)?$'
+  # no-restricted-syntax needs the repository's config module path;
+  # package-size is the gap linter's
+  FX_ROUTED_SKIP='no-restricted-syntax package-size'
+  FX_LENGTH_RULE='sonarjs/max-lines'
   FX_LINTER_COMMENT='//'
   FX_EXT='.ts'
   FX_LINE_COMMENT='// note'
diff --git a/ts-react-linter-driven-development/setup/eslint.config.ldd.mjs b/ts-react-linter-driven-development/setup/eslint.config.ldd.mjs
new file mode 100644
index 0000000..85da438
--- /dev/null
+++ b/ts-react-linter-driven-development/setup/eslint.config.ldd.mjs
@@ -0,0 +1,115 @@
+// Recommended ESLint flat-config fragment of the linter-driven-development
+// plugins: every rule the plugin's routing table routes to one of the twelve
+// design rules, at the limits the rules name. Each rule line says which rule its
+// failures feed. The plugin never writes this file into a repository: the
+// repository's owners copy it, or the parts they want, beside eslint.config.js
+// and spread it before their own entries. Later entries win, so every limit the
+// repository's config already sets stays the repository's:
+//
+//   import ldd from './eslint.config.ldd.mjs'
+//   export default [...ldd, ...yourConfig]
+//
+// residue-exempt: an ESLint configuration names its plugins and rules on purpose.
+// It needs eslint-plugin-sonarjs, eslint-plugin-react, eslint-plugin-react-hooks,
+// eslint-plugin-promise, eslint-plugin-import and typescript-eslint; a repository
+// that does not use one of them leaves its rules out. The @typescript-eslint rules
+// below need type information: the repository's config sets typescript-eslint's
+// parser with parserOptions.projectService for these files, or ESLint stops with
+// an error. Limits a repository already sets stay the repository's: the linter is
+// the authority for every threshold it holds. Rules this file leaves out (style,
+// imports, formatting) are the repository's own choice, and so is
+// no-restricted-syntax on import.meta.env outside the config module (R8): the
+// config module's path is the repository's.
+//
+// Adopt it on an existing codebase with ESLint's bulk suppressions: run
+// `npx eslint --suppress-all` once to record today's violations, so only new ones
+// fail; `npx eslint --prune-suppressions` drops the entries that are fixed.
+
+import importPlugin from 'eslint-plugin-import'
+import promise from 'eslint-plugin-promise'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import sonarjs from 'eslint-plugin-sonarjs'
+import tseslint from 'typescript-eslint'
+
+export default [
+  {
+    files: ['**/*.{ts,tsx}'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+      import: importPlugin,
+      promise,
+      react,
+      'react-hooks': reactHooks,
+      sonarjs,
+    },
+    rules: {
+      // R3 storifying
+      'sonarjs/cognitive-complexity': ['error', 15],
+      'sonarjs/cyclomatic-complexity': ['error', { threshold: 10 }],
+      'sonarjs/expression-complexity': ['error', { max: 5 }],
+      // R3's limits: more than 50 lines or more than 2 nesting levels
+      'sonarjs/max-lines-per-function': ['error', { maximum: 50 }],
+      'sonarjs/nested-control-flow': ['error', { maximumNestingLevel: 2 }],
+      'sonarjs/no-nested-conditional': 'error',
+      'sonarjs/no-nested-functions': 'error',
+      'sonarjs/elseif-without-else': 'error',
+      'react/no-unstable-nested-components': 'error',
+      // R1 primitive obsession
+      'max-params': ['error', 4],
+      'sonarjs/no-duplicate-string': ['error', { threshold: 3 }],
+      'sonarjs/max-union-size': ['error', { threshold: 4 }],
+      'sonarjs/no-identical-functions': 'error',
+      'react/no-array-index-key': 'error',
+      'no-magic-numbers': ['error', {
+        ignore: [-1, 0, 1, 2],
+        ignoreArrayIndexes: true,
+        ignoreDefaultValues: true,
+        ignoreClassFieldInitialValues: true,
+        detectObjects: false,
+      }],
+      // R2 self-validating types: parse at the boundary
+      '@typescript-eslint/no-explicit-any': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'error',
+      '@typescript-eslint/no-unsafe-assignment': 'error',
+      '@typescript-eslint/no-unsafe-call': 'error',
+      '@typescript-eslint/no-unsafe-member-access': 'error',
+      '@typescript-eslint/no-unsafe-return': 'error',
+      '@typescript-eslint/no-unnecessary-condition': 'error',
+      // R5 vertical slice: one juicy module per file; counts code lines only
+      'sonarjs/max-lines': ['error', { maximum: 450 }],
+      'react/no-multi-comp': ['error', { ignoreStateless: false }],
+      // R8 no globals
+      'import/no-mutable-exports': 'error',
+      // R10 concurrency safety
+      'react-hooks/exhaustive-deps': 'error',
+      'react-hooks/set-state-in-effect': 'error',
+      '@typescript-eslint/no-floating-promises': 'error',
+      '@typescript-eslint/no-misused-promises': 'error',
+      'promise/catch-or-return': 'error',
+      // R11 conditional dispatch
+      '@typescript-eslint/switch-exhaustiveness-check': 'error',
+      'sonarjs/no-nested-switch': 'error',
+      'sonarjs/max-switch-cases': 'error',
+      'sonarjs/no-small-switch': 'error',
+      // R12 mutation discipline
+      'no-param-reassign': ['error', { props: true }],
+      'sonarjs/prefer-read-only-props': 'error',
+      'react/no-direct-mutation-state': 'error',
+    },
+  },
+  {
+    // Tests are long and repeat literals by design.
+    files: ['**/*.test.{ts,tsx}', '**/*.spec.{ts,tsx}'],
+    rules: {
+      'sonarjs/max-lines-per-function': 'off',
+      'sonarjs/no-duplicate-string': 'off',
+      'sonarjs/no-nested-functions': 'off',
+      'max-params': 'off',
+      'no-magic-numbers': 'off',
+      'react/no-multi-comp': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+    },
+  },
+]
diff --git a/ts-react-linter-driven-development/setup/golangci.yaml b/ts-react-linter-driven-development/setup/golangci.yaml
new file mode 100644
index 0000000..fd73147
--- /dev/null
+++ b/ts-react-linter-driven-development/setup/golangci.yaml
@@ -0,0 +1,86 @@
+# Recommended golangci-lint v2 configuration of the linter-driven-development
+# plugins: every linter rule the plugin's routing table routes to one of the
+# twelve design rules, at the limits the rules name. Each linter line says which
+# rule its failures feed. The plugin never writes this file into a repository:
+# the repository's owners copy it, or the parts they want, into .golangci.yaml.
+# residue-exempt: a golangci-lint configuration names its linters on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# naming, formatting) are the repository's own choice.
+#
+# Adopt it on an existing codebase with the ratchet below: only issues in code
+# changed since the merge base with main fail, so old code is not a wall of
+# findings on day one. CI needs main in the clone for it (fetch-depth: 0 in
+# GitHub Actions). Remove the ratchet once the old findings are gone.
+# gocyclo stands for the routing table's "gocyclo / cyclop": enable one of the two.
+
+version: "2"
+
+issues:
+  new-from-merge-base: main
+
+linters:
+  # The standard set (errcheck, govet, ineffassign, staticcheck, unused) stays on;
+  # the linters below are added to it.
+  default: standard
+  enable:
+    - gocyclo           # R3 storifying: cyclomatic complexity
+    - gocognit          # R3 storifying: cognitive complexity
+    - funlen            # R3 storifying: function length
+    - nestif            # R3 storifying: nesting depth
+    - maintidx          # R3 storifying, R1 types: maintainability index
+    - dupl              # R1 types: duplicated logic; a duplicated switch is R11
+    - exhaustive        # R11 conditional dispatch: missing enum cases
+    - gochecknoglobals  # R8 no globals
+    - gochecknoinits    # R8 no globals
+    - ireturn           # R6 test-only interfaces: a constructor that returns an interface
+    - govet             # R10 concurrency: copylocks
+    - revive            # R1 types, R5 vertical slice: the rules below
+    - errcheck          # mechanical: an error that is not handled
+    - wrapcheck         # mechanical: an error without the context of its layer
+    - goconst           # mechanical; an enum-shaped string is R1's "Name enum strings"
+  settings:
+    gocyclo:
+      min-complexity: 10
+    gocognit:
+      min-complexity: 15
+    funlen:
+      lines: 50
+      statements: 40
+    nestif:
+      min-complexity: 2
+    maintidx:
+      under: 20
+    dupl:
+      threshold: 100
+    exhaustive:
+      # A default branch does not count as handling a case: every new case is
+      # handled where the switch is.
+      default-signifies-exhaustive: false
+    govet:
+      enable:
+        - copylocks
+    goconst:
+      min-len: 3
+      min-occurrences: 3
+    revive:
+      rules:
+        - name: argument-limit          # R1: more than 4 parameters wants a parameter object
+          arguments: [4]
+        - name: function-result-limit   # R1: more than 3 results wants a named result type
+          arguments: [3]
+        - name: file-length-limit       # R5: one juicy type per file; counts code lines only
+          arguments: [{max: 450, skip-comments: true, skip-blank-lines: true}]
+        - name: early-return            # mechanical: invert the condition and return early
+  exclusions:
+    rules:
+      # Tests are long and repeat literals by design.
+      - path: _test\.go
+        linters:
+          - funlen
+          - gocognit
+          - gocyclo
+          - maintidx
+          - dupl
+          - goconst
diff --git a/ts-react-linter-driven-development/setup/ruff.toml b/ts-react-linter-driven-development/setup/ruff.toml
new file mode 100644
index 0000000..03571ca
--- /dev/null
+++ b/ts-react-linter-driven-development/setup/ruff.toml
@@ -0,0 +1,58 @@
+# Recommended ruff configuration of the linter-driven-development plugins:
+# every rule the plugin's routing table routes to one of the twelve design
+# rules, at the limits the rules name. Each rule says which rule its failures
+# feed. The plugin never writes this file into a repository: the repository's
+# owners copy it, or the parts they want, into ruff.toml, or into
+# pyproject.toml with each table name prefixed by "tool.ruff." ([lint] becomes
+# [tool.ruff.lint]).
+# residue-exempt: a ruff configuration names its rule codes on purpose.
+#
+# Limits a repository already sets stay the repository's: the linter is the
+# authority for every threshold it holds. Rules this file leaves out (style,
+# docstrings, imports) are the repository's own choice. ruff has no file-length
+# rule: the plugin's gap linter, scripts/ldd-lint.sh file-length, holds that
+# limit at 450 code lines.
+#
+# Adopt it on an existing codebase one change at a time: run ruff on the files
+# changed since the merge base with main, so old code is not a wall of
+# findings on day one:
+#   git diff -z --name-only --diff-filter=d "$(git merge-base HEAD main)" -- '*.py' \
+#     | xargs -0 sh -c '[ "$#" -eq 0 ] || ruff check "$@"' sh
+# The sh guard keeps an empty change list from checking the whole repository,
+# and -z with -0 keeps a path with spaces whole.
+
+[lint]
+# PLR1702 (nested blocks) is a preview rule. Preview mode also turns on preview
+# behavior of the stable rules a repository already selects; a repository that
+# does not want that drops these two lines and PLR1702.
+preview = true
+explicit-preview-rules = true
+extend-select = [
+  "C901",     # R3 storifying: complexity
+  "PLR0911",  # R3 storifying: too many returns
+  "PLR0912",  # R3 storifying: too many branches
+  "PLR0915",  # R3 storifying: too many statements
+  "PLR1702",  # R3 storifying: nesting
+  "PLR0913",  # R1 types: too many arguments wants a parameter object
+  "PLR2004",  # R1 types: a magic value; an enum-shaped string is "Name enum strings"
+  "FBT001",   # R11 conditional dispatch: a boolean positional parameter
+  "FBT002",   # R11 conditional dispatch: a boolean default parameter
+  "PLW0603",  # R8 no globals: a global statement
+  "B006",     # R12 mutation discipline: a mutable default argument
+  "B008",     # R12 mutation discipline: a call in a default argument
+]
+
+[lint.mccabe]
+max-complexity = 8
+
+[lint.pylint]
+max-args = 4          # self and cls are not counted
+max-branches = 12
+max-returns = 6
+max-statements = 50
+max-nested-blocks = 2  # R3: more than 2 nesting levels
+
+[lint.per-file-ignores]
+# Tests repeat literals and take many fixtures by design.
+"**/test_*.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]
+"**/*_test.py" = ["PLR2004", "PLR0913", "FBT001", "FBT002"]