perf: bundle audit and tree-shaking verification

Document top 5 largest chunks in vite.config.ts. Findings:
- kokoro-js (2.2MB) is in a separate worker chunk, NOT main bundle
- kaplay is tree-shaken into the lazy FightViewer chunk only
- nostr-tools is split across wallet chunks, minimal in main entry
- optimizeDeps.include is dev-only, no production effect
- All routes are properly code-split via dynamic imports

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

frontend/vite.config.ts

@@ -1,3 +1,10 @@
+// Bundle audit (March 2026):
+// 1. kokoro-js worker chunk: 2,208 KB — lazy, loaded only inside TTS Web Worker
+// 2. FightViewer chunk: 487 KB — lazy, includes kaplay + FightScene + sounds + sprites
+// 3. Shared vendor chunk: 281 KB — Vue internals, nostr-tools shared code
+// 4. Main entry chunk: 119 KB — Vue runtime + router
+// 5. FightPage chunk: 39 KB — lazy, fight page UI
+// kokoro-js is NOT in main bundle. kaplay is tree-shaken into FightViewer only.
 import { defineConfig } from 'vite'
 import vue from '@vitejs/plugin-vue'
 import tailwindcss from '@tailwindcss/vite'