Pass .env to the service container so DB credentials resolve

Without env_file on the service block, the app container had no
POSTGRES_USER/POSTGRES_PASSWORD/etc. in its environment, so
${VAR} placeholders in endpoints.yaml were left unexpanded.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: arnellebalane

docker-compose.yml

@@ -15,6 +15,7 @@ services:
 
   service:
     build: .
+    env_file: .env
     ports:
       - 3001:8080
     restart: unless-stopped