feat: add stateful responses API

backend/app.py

@@ -25,6 +25,7 @@ import settings
 import uvicorn
 from db.session import sync_default_tools, sync_interface_definitions
 from services.knowledge import recover_interrupted_documents
+from services.openai_responses.state import recover_interrupted_responses
 from services.post_call.worker import recover_interrupted_analyses, run_analysis_worker
 from services.webhooks.worker import recover_interrupted_webhooks, run_webhook_worker
 from services.test_runs.orchestrator import (
@@ -45,6 +46,7 @@ from routes import (
     model_registry,
     node_types,
     openai_realtime,
+    openai_responses,
     realtime_api_keys,
     site_settings,
     test_cases,
@@ -64,6 +66,7 @@ async def lifespan(_app: FastAPI):
     await recover_interrupted_analyses()
     await recover_interrupted_webhooks()
     await recover_interrupted_test_runs()
+    await recover_interrupted_responses()
     analysis_worker = asyncio.create_task(
         run_analysis_worker(), name="post-call-analysis-worker"
     )
@@ -102,6 +105,7 @@ app.include_router(mcp_servers.router)
 app.include_router(model_registry.router)
 app.include_router(node_types.router)
 app.include_router(openai_realtime.router)
+app.include_router(openai_responses.router)
 app.include_router(realtime_api_keys.router)
 app.include_router(site_settings.router)
 app.include_router(test_cases.router)