The shared postgis container is bound to 127.0.0.1 on the host (security
hardening, infrastructure §T12). Ollama is similarly LAN-hardened. The
previous `host.docker.internal + extra_hosts: host-gateway` approach
points at the bridge gateway IP, not loopback, so the container couldn't
reach either service.
Switch to `network_mode: host` (same pattern goldstein uses) and update
the default IX_POSTGRES_URL / IX_OLLAMA_URL to 127.0.0.1. Keep the GPU
reservation block; drop the now-meaningless ports: declaration (host mode
publishes directly).
AppConfig defaults + .env.example + test_config assertions + inline
docstring examples all follow.
Caught on fourth deploy attempt.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>