Fix Vercel serverless deployment: optimize for fast loading

- Convert Express app to Vercel serverless function
- Add missing /api/files/public endpoint
- Optimize static file routing with proper caching
- Remove unnecessary dependencies for faster cold starts
- Add comprehensive debugging and error handling
- Improve API response times and user experience

.claude/settings.local.json

@@ -36,7 +36,8 @@
       "Bash(tasklist)",
       "Bash(start http://localhost:8000)",
       "Bash(npm --version)",
-      "mcp__sequential-thinking__sequentialthinking"
+      "mcp__sequential-thinking__sequentialthinking",
+      "Bash(git commit:*)"
     ],
     "deny": [],
     "ask": [],