feat: implement ai topic difficulty analyzer (#85)

.env.example

@@ -30,6 +30,33 @@ RAZORPAY_SECRET_KEY=your_razorpay_secret_here
 # Get from: https://aistudio.google.com/app/apikey
 GEMINI_API_KEY=your-gemini-api-key-here
 
+# ── App ───────────────────────────────────────────────────────
+# Your deployed URL (no trailing slash)
+# Development: http://localhost:3000
+# Production: https://yourdomain.com
+NEXT_PUBLIC_SITE_URL=http://localhost:3000
+NEXT_PUBLIC_SUPABASE_URL=https://your-project-id.supabase.co
+
+# Anon/public key (safe to expose to client)
+NEXT_PUBLIC_SUPABASE_ANON_KEY=your-anon-key-here
+
+# Service role key — NEVER expose to client, server-side only
+SUPABASE_SERVICE_ROLE_KEY=your-service-role-key-here
+
+# ── Razorpay ──────────────────────────────────────────────────
+# Found in: Razorpay Dashboard → Settings → API Keys
+# Use TEST keys during development
+
+# Test key ID (starts with rzp_test_)
+RAZORPAY_KEY_ID=rzp_test_your_key_id_here
+
+# Secret key — server-side only, NEVER expose to client
+RAZORPAY_SECRET_KEY=your_razorpay_secret_here
+
+# ── Google AI (Gemini) ────────────────────────────────────────
+# Get from: https://aistudio.google.com/app/apikey
+GEMINI_API_KEY=your-gemini-api-key-here
+
 # ── App ───────────────────────────────────────────────────────
 # Your deployed URL (no trailing slash)
 # Development: http://localhost:3000

components/dashboard/sidebar.tsx

@@ -39,7 +39,6 @@ const navItems = [
   { icon: Network,           label: "Concept Map",href: "/concept-map",                  guestOk: false },
   { icon: Calendar,          label: "Planner",    href: "/planner",                      guestOk: false },
   { icon: Sparkles,          label: "Topic Analyzer", href: "/topic-analyzer",           guestOk: false },
-  { icon: Trophy,            label: "Goals & Badges", href: "/goals",                   guestOk: false },
   { icon: BookOpen,          label: "Blogs",      href: "/blogs",      external: true,  guestOk: true  },
 ]