feat(pipeline): add batch API status + result processing endpoints

- GET /generate/batch-api-status/{batch_id} — check Anthropic batch status
- POST /generate/process-batch — process completed batch results (background)
- GET /generate/process-batch-status/{job_id} — poll processing progress

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

control-pipeline/api/control_generator_routes.py

@@ -2233,3 +2233,61 @@ async def get_harmonization_recheck_status(job_id: str):
     if not status:
         raise HTTPException(status_code=404, detail="Harmonization recheck job not found")
     return status
+
+
+# =============================================================================
+# BATCH API: STATUS + RESULT PROCESSING
+# =============================================================================
+
+@router.get("/generate/batch-api-status/{batch_id}")
+async def get_batch_api_status(batch_id: str):
+    """Check status of an Anthropic Batch API job."""
+    from services.decomposition_pass import check_batch_status
+    status = await check_batch_status(batch_id)
+    return status
+
+
+class ProcessBatchRequest(BaseModel):
+    batch_id: str
+    pass_type: str = "0b"  # "0a" or "0b"
+
+
+_batch_process_status: dict = {}
+
+
+async def _run_batch_processing(req: ProcessBatchRequest, job_id: str):
+    """Process batch results in background."""
+    from services.decomposition_pass import DecompositionPass
+    db = SessionLocal()
+    try:
+        _batch_process_status[job_id] = {"status": "running", "phase": "processing"}
+        dp = DecompositionPass(db)
+        result = await dp.process_batch_results(req.batch_id, req.pass_type)
+        _batch_process_status[job_id] = {"status": "completed", **result}
+    except Exception as e:
+        logger.error("Batch processing %s failed: %s", job_id, e)
+        _batch_process_status[job_id] = {"status": "failed", "error": str(e)}
+    finally:
+        db.close()
+
+
+@router.post("/generate/process-batch")
+async def process_batch(req: ProcessBatchRequest):
+    """Process results from a completed Anthropic Batch API job."""
+    import uuid
+    job_id = str(uuid.uuid4())[:8]
+    _batch_process_status[job_id] = {"status": "starting"}
+    asyncio.create_task(_run_batch_processing(req, job_id))
+    return {
+        "status": "running", "job_id": job_id,
+        "message": f"Batch processing started. Poll /generate/process-batch-status/{job_id}",
+    }
+
+
+@router.get("/generate/process-batch-status/{job_id}")
+async def get_batch_process_status(job_id: str):
+    """Get status of batch result processing."""
+    status = _batch_process_status.get(job_id)
+    if not status:
+        raise HTTPException(status_code=404, detail="Batch processing job not found")
+    return status