add lean

fnl/plugins/init.fnl

@@ -163,6 +163,23 @@
             (let [roslyn (require :roslyn)]
               (roslyn.setup {})))}
 
+ ;; lean.nvim - Lean 4 support: LSP (via `lake serve`), infoview, unicode
+ ;; abbreviations (\to -> →), :Telescope loogle. Self-activates on *.lean and
+ ;; registers its own LSP client, so no vim.lsp.config entry is needed.
+ ;; Needs `lake`/`lean` on PATH (elan, ~/.elan/bin); :init prepends it so a
+ ;; stale parent shell/tmux PATH doesn't cause "language server not installed".
+ ;; Configured via vim.g.lean_config; require("lean").setup is deprecated, so
+ ;; :config is disabled to keep lazy.nvim from calling it through :opts.
+ {repo "Julian/lean.nvim"
+  :event ["BufReadPre *.lean" "BufNewFile *.lean"]
+  :init (fn []
+          (let [elan-bin (vim.fn.expand "~/.elan/bin")]
+            (when (and (= 1 (vim.fn.isdirectory elan-bin))
+                       (not (vim.startswith vim.env.PATH (.. elan-bin ":"))))
+              (set vim.env.PATH (.. elan-bin ":" vim.env.PATH))))
+          (set vim.g.lean_config {:mappings true}))
+  :config false}
+
  ;; marks.nvim - Show mark letters in the sign column
  {repo "chentoast/marks.nvim"
   :event "VeryLazy"