feat(backend): register analytics, leaderboard, and profile routes in server

Add missing route registrations to complete the analytics, leaderboard, and profile features:
- Import analyticsRoutes from routes/analytics
- Import leaderboardRoutes from routes/leaderboard
- Register /api/profile endpoint with profileRoutes
- Register /api/analytics endpoint with analyticsRoutes
- Register /api/leaderboard endpoint with leaderboardRoutes

These routes enable:
- Comprehensive analytics dashboard with overview, activity trends, and top contributors
- Global, weekly, monthly, and friends leaderboards with user rankings
- User profile management with avatar upload and privacy settings

Dependencies: All route handlers, tests, and frontend components already implemented

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/server.js

@@ -138,6 +138,8 @@ const paymentRoutes = require("./routes/payments");
 const userRoutes = require("./routes/users");
 const cacheRoutes = require("./routes/cache");
 const profileRoutes = require("./routes/profile");
+const analyticsRoutes = require("./routes/analytics");
+const leaderboardRoutes = require("./routes/leaderboard");
 
 // Apply rate limiters
 app.use("/api/auth/register", authLimiter);
@@ -239,6 +241,7 @@ app.use("/api/ai", aiRoutes);
 app.use("/api/payments", paymentRoutes);
 app.use("/api/users", userRoutes);
 app.use("/api/cache", cacheRoutes);
+app.use("/api/profile", profileRoutes);
 app.use("/api/analytics", analyticsRoutes);
 app.use("/api/leaderboard", leaderboardRoutes);