Use Pierre Diffs edit mode for in-app file editing and persist unsaved drafts

README.md

@@ -194,8 +194,8 @@ and the live Diff settings preview.
 - **Command palette (⌘K)** — fuzzy search across commands, branches, tags,
   files, commits, and recent repos, with scope filtering and full keyboard +
   screen-reader operability.
-- **Work file documents** — edit syntax-highlighted working-tree files or
-  inspect historical source read-only; `--follow` history,
+- **Work file documents** — edit working-tree files with Pierre Diffs edit mode
+  (unsaved drafts persist while navigating) or inspect historical source read-only; `--follow` history,
   compare any two revisions, blame, and rendered previews for markdown and SVG; the Files tree
   uses the local filesystem listing directly, including muted Git-ignored
   paths, while overlaying current Git-state colors and recognizable language

ROADMAP.md

@@ -2220,14 +2220,12 @@ loadable while `.git` stays inaccessible; the snapshot/status hot path remains
 unchanged.
 
 **Syntax-highlighted file editing shipped (2026-07-19):** Opening an existing
-UTF-8 working-tree file from Files now mounts a lightweight editor backed by
-Pierre's shared Shiki tokenizer. Save and Mod+S explicitly write through
+UTF-8 working-tree file from Files now mounts Pierre Diffs edit mode. Save and Mod+S explicitly write through
 `repo_file_write`; the core preserves consistent CRLF endings and
 rejects stale, traversal, symlink, binary, non-UTF-8, and oversized writes.
-Historical revisions remain read-only. The editor projects the last Shiki token
-colors onto each new buffer immediately, so background retokenization never
-causes a plain-text flash while typing. Its in-memory buffer is LF-normalized
-for textarea/Shiki agreement while the core retains and restores the exact CRLF
+Historical revisions remain read-only. Unsaved working-tree drafts now stay in
+memory when users switch files, tabs, repositories, or Work panes, but writes
+remain explicit-only; the core retains and restores the exact CRLF
 disk form on save.
 
 **Files creation toolbar refined (2026-07-19):** The separate New file and New

TASKS.md

@@ -1208,16 +1208,14 @@ Detailed comparison and sequencing: [`docs/git-client-1.0-audit.md`](./docs/git-
 - ☑ Tab strip + header (opened via `selectFile` from the Files tab / palette;
   a Close action returns to Local Changes)
 - ☑ Content tab — working-tree (or revision) content via `repo_file_content`.
-  Existing complete UTF-8 working-tree files edit through the syntax-highlighted
-  `HighlightedEditor` and save through stale-checked `repo_file_write`; revisions,
-  binaries, oversized files, and non-UTF-8 text stay on Pierre's read-only
-  `<File>`. Optimistic token projection keeps the last Shiki colors attached
-  to unchanged text during every edit—there is no plain-text refresh frame—and
-  reconstructs CRLF token streams without tripping the plain-text fallback.
+  Existing complete UTF-8 working-tree files edit through Pierre Diffs edit mode
+  (`EditProvider`/`Editor`) and save through stale-checked `repo_file_write`;
+  revisions, binaries, oversized files, and non-UTF-8 text stay on Pierre's
+  read-only `<File>`.
   Writes are explicit only, via the disk save icon or Mod+S; blur and idle time
-  never save a draft. Focus/watcher refreshes keep the mounted editor and token
-  map in place, and a refresh that finishes after typing starts cannot replace
-  the draft (`ContentTab` loaded-source/dirty guards).
+  never save a draft. Unsaved drafts stay in memory when navigating around
+  Strand. Focus/watcher refreshes keep the mounted editor state in place, and a refresh that finishes
+  after typing starts cannot replace the draft (`ContentTab` loaded-source/dirty guards).
   Mod+F searches the source with wrap-around match navigation and
   virtualized-line scrolling (`FileSearchBar` + `searchFileText`).
 - ☑ Preview tab — rendered view for renderable text files, tab only offered

ui/package.json

@@ -15,7 +15,7 @@
     "doctor": "npx react-doctor@latest"
   },
   "dependencies": {
-    "@pierre/diffs": "^1.2.3",
+    "@pierre/diffs": "^1.3.3",
     "@pierre/theme": "1.1.0",
     "@pierre/trees": "1.0.0-beta.5",
     "@tauri-apps/api": "^2",

ui/src/lib/fileEditing.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest';
 
-import { canEditFileContent } from './fileEditing';
+import { canEditFileContent, fileDraftKey } from './fileEditing';
 
 describe('file content editing', () => {
   it('keeps accepted working-tree text editable in every presentation', () => {
@@ -11,4 +11,10 @@ describe('file content editing', () => {
     expect(canEditFileContent(true, 'abc123')).toBe(false);
     expect(canEditFileContent(false, null)).toBe(false);
   });
+
+  it('keys unsaved drafts only for working-tree files', () => {
+    expect(fileDraftKey('/repo', 'src/main.ts', null)).toBe('/repo\u0000src/main.ts');
+    expect(fileDraftKey('/repo', 'src/main.ts', 'abc123')).toBe(null);
+    expect(fileDraftKey(null, 'src/main.ts', null)).toBe(null);
+  });
 });

ui/src/lib/fileEditing.ts

@@ -4,3 +4,8 @@
 export function canEditFileContent(editable: boolean, revision: string | null): boolean {
   return editable && revision === null;
 }
+
+export function fileDraftKey(repoPath: string | null, path: string, revision: string | null): string | null {
+  if (!repoPath || revision !== null) return null;
+  return `${repoPath}\u0000${path}`;
+}