Add landing page, referral system, usage quotas, search API management, and yearly pricing

- Separate workspace landing from login for better UX
- Referral system rewards both parties with Pro days
- Quota enforcement prevents abuse without breaking endpoints
- 7-day free trial with auto-downgrade on expiry
- Admin-managed search provider config (SearXNG, Bing)
- 15% discount on annual subscriptions
- MCP search server wrapping opencode search
- Fix discovery module field name mismatch causing 422

backend/app/api/v1/search.py

@@ -0,0 +1,19 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.ext.asyncio import AsyncSession
+from app.database import get_db
+from app.api.v1.deps import get_current_user_id
+from app.services.search import SearchService
+
+router = APIRouter()
+
+
+@router.get("/query")
+async def search(
+    q: str = Query(..., min_length=1, max_length=500),
+    limit: int = Query(10, ge=1, le=50),
+    user_id: str = Depends(get_current_user_id),
+    db: AsyncSession = Depends(get_db),
+):
+    svc = SearchService(db)
+    results = await svc.search(q, limit)
+    return {"query": q, "results": results}