perf: V8 compile cache, lazy-load WebGL, preload hints, batch tmux reconciliation

- Enable NODE_COMPILE_CACHE in systemd service and npm start for 10-20% faster cold starts
- Lazy-load xterm-addon-webgl.min.js (244KB) only on desktop — mobile never downloads it
- Add <link rel="preload"> hints for critical scripts (xterm, constants, app) in <head>
- Replace per-session tmux subprocess calls with single batch `list-panes -a` call
  (N*2+1+M execSync calls → 1 for reconcileSessions)
- Fix CLAUDE.md frontend module count (10 → 11)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -11,7 +11,7 @@
   "scripts": {
     "postinstall": "node scripts/postinstall.js",
     "build": "node scripts/build.mjs",
-    "start": "node dist/index.js",
+    "start": "NODE_COMPILE_CACHE=${HOME}/.codeman/compile-cache node dist/index.js",
     "dev": "tsx src/index.ts web",
     "web": "node dist/index.js web",
     "clean": "rm -rf dist",