fix: relax api→postgres dependency to service_started+restart

depends_on: condition: service_healthy on the api service was
failing during docker compose up because postgres hasn't completed
its healthcheck yet (start_period=30s). Changed to
condition: service_started with restart: true so the API
starts as soon as postgres is running and retries if the
DB isn't ready yet. The .NET backend already handles
transient DB connection failures.

compose.yaml

@@ -63,7 +63,8 @@ services:
       - host.docker.internal:host-gateway
     depends_on:
       postgres:
-        condition: service_healthy
+        condition: service_started
+        restart: true
     healthcheck:
       test: ["CMD-SHELL", "wget --no-verbose --tries=1 --spider http://localhost:8080/health/live || exit 1"]
       interval: 30s