feat: discovery-first tool resolution (make Mason optional)

lua/core/settings.lua

@@ -84,23 +84,15 @@ settings["external_browser"] = "chrome-cli open"
 ---@type boolean
 settings["lsp_inlayhints"] = false
 
--- LSPs installed outside Mason (e.g. via system package manager).
--- These will be configured but not installed by Mason.
--- Key: lspconfig server name, Value: executable name to check availability.
----@type table<string, string>
-settings["external_lsp_deps"] = {
-	nixd = "nixd",
-	nil_ls = "nil",
-	shuck = "shuck", -- shell linter/formatter/LSP (Rust); installed via mise, not Mason
-	-- dartls = "dart",
-}
-
--- LSPs to install during bootstrap.
+-- Language servers to enable, resolved discovery-first at runtime: binary on $PATH is
+-- used as-is; else Mason installs it when it ships a package; else an aggregated warning
+-- asks you to provision it. See `modules.utils.tools` and `completion/mason-lspconfig.lua`.
 -- Full list: https://github.com/neovim/nvim-lspconfig/tree/master/lsp
 ---@type string[]
 settings["lsp_deps"] = {
 	"bashls",
 	"clangd",
+	-- "dartls", -- Dart LSP (ships with the Dart SDK)
 	"dockerls",
 	"gh_actions_ls",
 	-- "gitlab_ci_ls",
@@ -111,7 +103,10 @@ settings["lsp_deps"] = {
 	"lua_ls",
 	"marksman",
 	"neocmake",
+	"nil_ls", -- Nix LSP; prefer the $PATH binary (Nix), else Mason installs it (package `nil`)
+	"nixd", -- Nix LSP (Rust); no Mason package, comes from Nix ($PATH)
 	"ruff",
+	"shuck", -- shell linter/formatter/LSP (Rust); no Mason package, installed via mise
 	"systemd_lsp",
 	"terraformls",
 	"tflint",
@@ -120,13 +115,13 @@ settings["lsp_deps"] = {
 	"zuban",
 }
 
--- Formatters to install during bootstrap (Mason package names).
--- These are managed by Mason and used by conform.nvim.
+-- Formatters to resolve when conform.nvim lazy-loads (first BufWritePre /
+-- :Format). conform formatter names, resolved discovery-first like lsp_deps.
 ---@type string[]
 settings["formatter_deps"] = {
 	"beautysh",
 	"clang-format",
-	"cmakelang",
+	"cmake_format",
 	"fixjson",
 	"gofumpt",
 	"goimports",
@@ -137,22 +132,29 @@ settings["formatter_deps"] = {
 	"stylua",
 }
 
--- Linters to install during bootstrap (Mason package names).
--- These are managed by Mason and used by nvim-lint.
+-- Linters to resolve when nvim-lint lazy-loads (first BufReadPost). nvim-lint
+-- linter names, resolved discovery-first like formatter_deps.
 ---@type string[]
 settings["linter_deps"] = {
 	"actionlint",
 	"hadolint",
 	"markdownlint-cli2",
 	"oxlint",
 	-- "rumdl", -- markdownlint Rust rewrite; waiting for rule coverage to mature
-	"golangci-lint",
+	"golangcilint",
 	"selene",
 	"shellcheck",
 	"systemdlint",
 }
 
--- Debug Adapter Protocol (DAP) clients to install and configure during bootstrap.
+-- Deadline (ms) for background Mason work before the aggregated missing-tool warning is
+-- flushed anyway, so one stalled download can't suppress it all session. A finished
+-- install past the deadline is still configured; non-positive values use the default.
+---@type number
+settings["tool_install_timeout"] = 300000
+
+-- DAP adapters to enable (mason-nvim-dap adapter names), resolved
+-- discovery-first when nvim-dap lazy-loads (first :Dap* command).
 -- Supported DAPs: https://github.com/jay-babu/mason-nvim-dap.nvim/blob/main/lua/mason-nvim-dap/mappings/source.lua
 ---@type string[]
 settings["dap_deps"] = {

lua/modules/configs/completion/conform.lua

@@ -168,6 +168,85 @@ return function()
 		end or false,
 	})
 
+	-- Resolve `formatter_deps` (conform formatter names) discovery-first against conform's
+	-- own registry. Runs synchronously before lazy.nvim replays BufWritePre so the
+	-- off-$PATH rewrite is in place for the first format-on-save under Mason PATH = "skip".
+	local tools = require("modules.utils.tools")
+	tools.resolve_runtime_tools("conform.nvim", settings.formatter_deps, function(name)
+		-- get_formatter_config is conform's @private API; if dropped, degrade to
+		-- "resolves itself" rather than misreporting every formatter as unknown.
+		local conform = require("conform")
+		if type(conform.get_formatter_config) ~= "function" then
+			return { binary = nil }
+		end
+		-- get_formatter_config runs a function-form override directly, so pcall keeps a
+		-- throwing override (a broken config) from being misread as an unknown name.
+		local ok, config, err = pcall(conform.get_formatter_config, name)
+		if not ok then
+			return { broken = tostring(config) }
+		end
+		if config then
+			if type(config.command) == "function" then
+				-- Function-form command (e.g. builtin `from_node_modules`): evaluate it with
+				-- a hand-built ctx for a representative answer; per-buffer differences are
+				-- covered by configure's wrapper below.
+				local buf = vim.api.nvim_get_current_buf()
+				local filename = vim.api.nvim_buf_get_name(buf)
+				local ok_cmd, cmd = pcall(config.command, config, {
+					buf = buf,
+					filename = filename,
+					dirname = vim.fs.dirname(filename),
+				})
+				if not ok_cmd then
+					return { broken = tostring(cmd) }
+				end
+				return { binary = type(cmd) == "string" and cmd or nil }
+			end
+			return { binary = config.command }
+		end
+		-- (nil, err) is a real formatter with a broken config; bare nil is an unknown name.
+		if type(err) == "string" then
+			return { broken = err }
+		end
+		return nil
+	end, function(name)
+		-- Under Mason PATH = "skip" the binary is off $PATH; rewrite it to an absolute
+		-- path so conform doesn't spawn a bare name that fails. No-op on $PATH.
+		local conform = require("conform")
+		local prev = conform.formatters[name]
+		if type(prev) == "function" then
+			-- Function-form override resolves per buffer: wrap it to rewrite an off-$PATH
+			-- result, preserving the override's args/cwd.
+			conform.formatters[name] = tools.wrap_off_path(prev, "command")
+			return
+		end
+		if type(conform.get_formatter_config) ~= "function" then
+			return
+		end
+		local config = conform.get_formatter_config(name)
+		if not config then
+			return
+		end
+		if type(config.command) == "function" then
+			-- Function-form command resolves per buffer: wrap it to rewrite an off-$PATH
+			-- result at format time; (self, ctx) pass through.
+			conform.formatters[name] = vim.tbl_deep_extend(
+				"force",
+				type(prev) == "table" and prev or {},
+				{ command = tools.wrap_off_path(config.command) }
+			)
+			return
+		end
+		if type(config.command) ~= "string" then
+			return
+		end
+		local abs = tools.off_path_command(config.command)
+		if abs then
+			conform.formatters[name] =
+				vim.tbl_deep_extend("force", type(prev) == "table" and prev or {}, { command = abs })
+		end
+	end)
+
 	-- User commands
 	vim.api.nvim_create_user_command("Format", function(args)
 		local range = nil

lua/modules/configs/completion/lsp.lua

@@ -1,29 +1,11 @@
 return function()
+	-- Server resolution (Mason-installed / on $PATH / installable / missing) is handled
+	-- discovery-first in `mason-lspconfig.setup`, driven by `settings.lsp_deps`.
 	require("completion.mason-lspconfig").setup()
 
-	local opts = {
-		capabilities = require("modules.utils").get_lsp_capabilities(),
-	}
-	-- Configure LSPs that are not managed by Mason but are available in `nvim-lspconfig`.
-	-- Servers are defined in `settings.external_lsp_deps` as { server_name = "executable" }.
-	for lsp_name, exe in pairs(require("core.settings").external_lsp_deps) do
-		if vim.fn.executable(exe) == 1 then
-			local ok, _opts = pcall(require, "user.configs.lsp-servers." .. lsp_name)
-			if not ok then
-				local default_ok, default_opts = pcall(require, "completion.servers." .. lsp_name)
-				if default_ok then
-					_opts = default_opts
-				end
-			end
-			if type(_opts) == "table" then
-				local final_opts = vim.tbl_deep_extend("keep", _opts, opts)
-				require("modules.utils").register_server(lsp_name, final_opts)
-			else
-				require("modules.utils").register_server(lsp_name, opts)
-			end
-		end
-	end
-
+	-- A server Mason installs mid-session registers only when its install finishes (after
+	-- this point), so a `vim.lsp.config` override here gets overwritten by the repo spec.
+	-- Overrides that must always win belong in `user.configs.lsp-servers.<name>`.
 	pcall(require, "user.configs.lsp")
 
 	-- Start LSPs