fix git monitor

CLAUDE.md

@@ -46,6 +46,7 @@ A dark-only (no light mode, no theme toggle) Electron desktop code workbench for
 - **Renderer never touches the filesystem, git, or PTYs directly.** All FS (`fs` + `chokidar`), git (`git` / `simple-git`), search (`rg` + fuzzy), terminals (`node-pty` + `xterm.js`), and clipboard go through the main process via IPC / the preload bridge. The prototype keeps all state in the top `App` component; in the real app, lift FS/git/terminal state into main and stream over IPC.
 - **Prism PHP load order:** `prism-php` requires `prism-markup-templating` to be loaded **first**, or every `Prism.highlight` call throws and silently falls back to plain text.
 - **Preload must be CommonJS `index.cjs`** and `main` must load `../preload/index.cjs` (see `electron.vite.config.ts` preload `rollupOptions.output`). If they mismatch (or you let it build as `.mjs`), Electron silently loads no preload, `window.helder` is undefined, and the renderer silently falls back to mock data + the "terminal not available" message. Keep the filename and the `main` path in sync.
+- **chokidar is pinned to v3 on purpose — do NOT bump to v4/v5.** chokidar ≥4 dropped the `fsevents` addon and watches recursively via libuv's native `fs.watch({recursive:true})`. On macOS that recursive watcher poisons the process's file descriptors, so every later `child_process.spawn` (i.e. every `git` call) fails with `spawn EBADF` (errno -9) and the git column silently stops updating. v3 uses the `fsevents` native addon instead and has no such conflict. If you must move to v4+, switch the main project watcher to `usePolling: true` (the only other config proven to avoid the EBADF here).
 - **Pass on to Agent uses bracketed paste.** Write inserts to the agent PTY wrapped in `\x1b[200~ … \x1b[201~` so the `claude` CLI treats it as *pasted, unsubmitted* input. Insert must never submit — it lands as a new line so the user can stack several references before sending.
 - **The four diff view modes (Original / Updated / Diff / Split) all derive from one original-text + updated-text pair per changed file.** The prototype computes this with an LCS line diff (`buildDiff()` in `design/src/data.js`); production should prefer real `git diff` output but keep the same four derived views and the same color language everywhere: **red = removed/changed-from, green = added/changed-to**, syntax highlighting on in all modes.
 - **The agent pane is just a terminal running the `claude` CLI** (`ai.command`, default `claude`, auto-launched when `ai.autoLaunch` is on). The bottom pane is a normal shell PTY. The prototype's simulated agent session (`agentSeed`, `runAgent`, `bootAgent` in `terminals.jsx`) exists only to show the visual style — keep the styling, drop the fakery.