fix(translate): handle row lock timeout in cancel, add flush fallback, migrate progress to store

- Extract _fallback_cancel_request for row lock timeout recovery in orchestrator_cancel
- Add flush lock timeout fallback in cancel_run
- Set error_message when all records fail in executor
- Track insert_failed state in scheduler and frontend store
- Migrate TranslationRunProgress from local polling to centralized store
- Fix nginx resolver for Docker variable-based proxy_pass
- Add FRONTEND_HOST_PORT env var to docker-compose

docker-compose.yml

@@ -53,7 +53,7 @@ services:
     depends_on:
       - backend
     ports:
-      - "8100:80"
+      - "${FRONTEND_HOST_PORT:-8000}:80"
 
 volumes:
   postgres_data: