fix: Update embedding dimensions to 3072 and add Vercel Analytics

- Updated GOOGLE_EMBEDDING_DIMENSIONS to 3072 to match gemini-embedding-001 output
- Updated database schema embedding index from 768 to 3072 dimensions
- Recreated production database index with correct dimensions
- Added @vercel/analytics package for production analytics
- Added Analytics component to root layout

This fixes the galaxy visualization issue caused by dimension mismatch between
the embedding model output (3072) and the database index (768).

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

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

package.json

@@ -25,6 +25,7 @@
     "@react-three/drei": "latest",
     "@react-three/fiber": "latest",
     "@tabler/icons-react": "^3.35.0",
+    "@vercel/analytics": "^1.5.0",
     "@xstate/react": "^6.0.0",
     "ai": "latest",
     "jsonwebtoken": "latest",