chore: add stripe server SDK, update .env.example with all platform env vars

Author: uet-santx

.env.example

@@ -27,3 +27,30 @@ GITHUB_CLIENT_SECRET=your-github-client-secret
 
 # ============= API Server =============
 API_PORT=3001
+NEXT_PUBLIC_API_URL=http://localhost:3001
+
+# ============= AI Agent =============
+OPENROUTER_API_KEY=sk-or-v1-your-key-here
+NEXT_PUBLIC_AGENT_URL=http://localhost:8001
+
+# ============= Rocket.Chat =============
+NEXT_PUBLIC_ROCKETCHAT_URL=http://localhost:3200
+RC_ADMIN_USERNAME=admin
+RC_ADMIN_PASS=admin123
+RC_ADMIN_EMAIL=admin@uet-platform.com
+
+# ============= LiveKit (Video/Voice) =============
+NEXT_PUBLIC_LIVEKIT_URL=ws://localhost:7880
+LIVEKIT_API_KEY=devkey
+LIVEKIT_API_SECRET=devsecret
+
+# ============= Stripe (Billing) =============
+STRIPE_SECRET_KEY=sk_test_your-stripe-secret-key
+NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=pk_test_your-stripe-publishable-key
+STRIPE_WEBHOOK_SECRET=whsec_your-webhook-secret
+
+# ============= Cloudflare R2 (Media Storage) =============
+R2_ACCOUNT_ID=your-account-id
+R2_ACCESS_KEY_ID=your-access-key
+R2_SECRET_ACCESS_KEY=your-secret-key
+R2_BUCKET_NAME=uet-media

uet_web/package-lock.json

@@ -57,6 +57,7 @@
     "remark-gfm": "^4.0.1",
     "remark-math": "^6.0.0",
     "shadcn": "^4.0.2",
+    "stripe": "^20.4.1",
     "tailwind-merge": "^3.5.0",
     "tailwind-scrollbar": "^4.0.2",
     "tailwindcss": "^4.2.1",