fix(web): fix getting-started metadata export, use TURBOPACK=0 env for build

- generateMetadata instead of metadata (getMetadata returns a function)
- Use TURBOPACK=0 env prefix instead of --no-turbopack flag (not recognized in Docker)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "build": "next build",
+    "build": "TURBOPACK=0 next build",
     "clean": "git clean -xdf .cache .next .turbo node_modules",
     "dev": "next dev",
     "format": "prettier --check . --ignore-path ../../.gitignore",