feat: add social features, leaderboard, auth enhancements, and admin fixes

- Implement Social Features: Shared Tasks, Global Access, Privacy Settings (Leaderboard/Searchable).
- Add Leaderboard Page and API.
- Enhance Auth: Support Email/Username login, explicit duplicate registration errors.
- Fix: Admin login password hash regression.
- Refactor: Move to wouter for routing, add Admin Dashboard and User Management.
- Add Setup Wizard.
- Update UI with Sidebar and Gamification elements.

server/index.ts

@@ -83,7 +83,7 @@ app.use((req, res, next) => {
     const message = err.message || "Internal Server Error";
 
     res.status(status).json({ message });
-    throw err;
+    // Don't throw err here, it crashes the server/socket after response is sent
   });
 
   // importantly only setup vite in development and after