Full webhook system: CRUD endpoints (list/filter/get/create/update/delete),
WebhookDelivery model for delivery audit trail, dispatch engine with 3-attempt
retry and exponential backoff, Celery task integration with sync fallback,
and webhook firing hooks in runner.py and sweep.py event paths.
Adds backend/engine/sweep.py with three sweep strategies:
- GridSweep: exhaustive enumeration of all parameter combinations
- RandomSweep: N random samples from parameter ranges (list, min/max, step)
- GuidedSweep: top-K exploitation + random exploration from previous results
Features: bounded parallelism via asyncio.Semaphore, token budget enforcement,
Redis-based pause/resume/stop control flags, sweep-level event publishing.
36 tests in test_sweep.py covering config generation, helpers, and full sweep execution.
