perf: feature-gate smart deps, drop ONNX/qdrant from backend binary

wiring `smart` feature gates fastembed+qdrant; bootstrap no longer
links ONNX Runtime (~300 MiB RSS savings). prod compose stripped
to backend-only (no worker/qdrant).

compose.prod.yml

@@ -9,58 +9,18 @@ services:
       - HOST=0.0.0.0
       - PORT=3000
       - ALLOW_REGISTRATION=false
-      - NATS_URL=nats://k_nats:4222
-      - QDRANT_URL=http://qdrant:6334
-      - QDRANT_COLLECTION=notes
-      # SPA is bundled in the image at /app/frontend/dist (set in Dockerfile)
-      # Override here only if you move the dist elsewhere:
-      # - SPA_DIR=/app/frontend/dist
     volumes:
       - ./data:/app/data
     networks:
       - traefik
-      - shared-services
-      - internal
     labels:
       - "traefik.enable=true"
       - "traefik.docker.network=traefik"
-      # Both the app domain and the API subdomain point to the same service.
-      # The backend serves /api/v1/* and falls back to the SPA for everything else.
       - "traefik.http.routers.knotes.rule=Host(`knotes.gabrielkaszewski.dev`) || Host(`api.knotes.gabrielkaszewski.dev`)"
       - "traefik.http.routers.knotes.entrypoints=websecure"
       - "traefik.http.routers.knotes.tls.certresolver=letsencrypt"
       - "traefik.http.services.knotes.loadbalancer.server.port=3000"
 
-  worker:
-    image: registry.gabrielkaszewski.dev/k-notes:latest
-    command: ["./worker"]
-    environment:
-      - DATABASE_URL=sqlite:///app/data/notes.db
-      - NATS_URL=nats://k_nats:4222
-      - QDRANT_URL=http://qdrant:6334
-      - ENABLE_EMBEDDINGS=true
-    depends_on:
-      - backend
-      - qdrant
-    volumes:
-      - ./data:/app/data
-    networks:
-      - internal
-      - shared-services
-
-  qdrant:
-    image: qdrant/qdrant:latest
-    container_name: k_notes_qdrant
-    volumes:
-      - ./data/qdrant_storage:/qdrant/storage:z
-    restart: unless-stopped
-    networks:
-      - internal
-
 networks:
   traefik:
     external: true
-  shared-services:
-    external: true
-  internal:
-    driver: bridge