feat(02-03): POST /api/intake handler with orchestrator and NetBox wiring
- IntakeHandler with IntakeOrchestrator/IntakeNetBoxClient/IntakeCatalogUpdater/IntakeWAQ interfaces
- Validates 1-3 photos, base64-encodes, calls Analyze, allocates HW-ID
- Quick-add mode: confidence >= threshold skips review, creates NetBox record immediately
- WAQ enqueue on NetBox failure returns 202 with queued=true
- nil WAQ + NetBox down returns 503
- Six unit tests: reject-0, reject-4, high-confidence, low-confidence, quick-add, netbox-down
- [Rule 1 - Bug] PatchCustomFields signature changed int -> int64 to match NetBoxOpsClient interface
- [Rule 1 - Bug] UpdateCatalogStatus signature changed int -> int64 for consistency with CreateDevice return type