fix: pass user to _run_job so get_user_gemini_key resolves correctly

NameError: name 'user' is not defined in orchestrator._run_job —
user was resolved in the endpoint but not forwarded to the background task.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cortex/routers/orchestrator.py

@@ -105,7 +105,7 @@ async def orchestrate(req: OrchestrateRequest) -> OrchestrateResponse:
         _jobs[job_id] = job
 
     # Run in background — caller polls GET /orchestrate/{job_id}
-    asyncio.create_task(_run_job(job_id, req))
+    asyncio.create_task(_run_job(job_id, req, user))
     logger.info("Orchestrator job queued: %s — %.80s", job_id, req.task)
     return OrchestrateResponse(job_id=job_id, status="queued")
 
@@ -135,7 +135,7 @@ async def list_jobs() -> list[JobStatusResponse]:
 # Background runner
 # ---------------------------------------------------------------------------
 
-async def _run_job(job_id: str, req: OrchestrateRequest) -> None:
+async def _run_job(job_id: str, req: OrchestrateRequest, user: str) -> None:
     """Execute the orchestration job and update the job store."""
     async with _jobs_lock:
         _jobs[job_id]["status"] = "running"