## Summary - stop deriving `APP_ORIGIN` from Coolify's internally generated HTTP service URL - keep the port-qualified magic variable solely as the proxy routing marker - document explicit production origins and the `https://${SERVICE_FQDN_APP}` Preview mapping for upstream TLS termination

## Testing - `docker compose --env-file .env.example -f compose.yaml config --quiet` - `docker compose --env-file .env.example -f compose.yaml -f compose.local.yaml config --quiet` - production interpolation resolves `APP_ORIGIN=https://chopin.githubnext.com` - Preview interpolation resolves `APP_ORIGIN=https://74-chopin.githubnext.com` and database host `db-pr-74` - `bun run ci`