fix: migrate deployment from Hetzner to Coolify (#1)

## Summary
- Add Coolify deployment configuration (docker-compose, healthchecks, network setup)
- Replace deploy-hetzner CI job with Coolify webhook deploy
- Externalize postgres, qdrant, S3 for Coolify environment
- Remove services not needed for SDK deployment (voice, jitsi, synapse)

## All changes since branch creation
- Coolify docker-compose with healthchecks for all services
- CI pipeline: deploy-hetzner → deploy-coolify (simple webhook curl)
- QDRANT_API_KEY support in rag-service
- Alpine-compatible Dockerfile fixes

Co-authored-by: Sharang Parnerkar <parnerkarsharang@gmail.com>
Reviewed-on: #1

rag-service/config.py

@@ -6,6 +6,7 @@ class Settings:
 
     # Qdrant
     QDRANT_URL: str = os.getenv("QDRANT_URL", "http://localhost:6333")
+    QDRANT_API_KEY: str = os.getenv("QDRANT_API_KEY", "")
 
     # MinIO
     MINIO_ENDPOINT: str = os.getenv("MINIO_ENDPOINT", "localhost:9000")