Remove custom network so Coolify/Traefik can route (fixes empty HTTPS reply)

Frontend was on two networks; Traefik (on only one) couldn't reach it -> 000/empty reply on HTTPS while nginx served 200 directly. Letting Coolify manage networking puts both services on its single proxy network; service-name DNS (backend) still resolves.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.yml

@@ -29,8 +29,6 @@ services:
       # Persist the SQLite file across container rebuilds.
       - visigine_data:/data
     restart: unless-stopped
-    networks:
-      - visigine
 
   frontend:
     build:
@@ -43,12 +41,6 @@ services:
       backend:
         condition: service_healthy
     restart: unless-stopped
-    networks:
-      - visigine
-
-networks:
-  visigine:
-    driver: bridge
 
 volumes:
   visigine_data: