Fix frigate live view by capping detect FPS (#204)

## Summary
- Cap detect FPS to 2 to prevent recording segment backlog from ONNX inference bottleneck (~750ms/frame on ARM64 CPU)
- Sync motion masks from live config (added second mask area)
- Update driveway_entrance zone coordinates from live config
- Add explicit alert labels `[person, car]` while keeping `required_zones: [driveway_entrance]`

## Context
The "No frames have been received" error on the gablecam live view was caused by the detect stream falling behind — ONNX YOLO-NAS-s takes ~750ms per inference on ARM64 CPU, but the sub-stream sends 5 FPS. This caused recording segments to pile up and the ffmpeg watchdog to repeatedly kill/restart the process, creating gaps in the live view.

## Test plan
- [ ] Sync ArgoCD `frigate` app to branch and verify pod restarts cleanly
- [ ] Check `/api/stats` — `skipped_fps` should drop significantly, `process_fps` should be close to 2
- [ ] Verify live view at https://nvr.ops.eblu.me/#gablecam no longer shows "No frames" error
- [ ] Verify detections and alerts still work in the driveway_entrance zone

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/204

argocd/manifests/frigate/configmap.yaml

@@ -30,18 +30,21 @@ data:
               roles: [detect]
         detect:
           enabled: true
+          fps: 2
           stationary:
             max_frames:
               default: 1500
         motion:
           mask:
             - 0.401,0.026,0.4,0.078,0.587,0.072,0.585,0.02
+            - 0.881,0.422,0.79,0.233,0.593,0.038,0.553,0,0.634,0,0.824,0.192,0.892,0.307
         zones:
           driveway_entrance:
-            coordinates: 0.85,0.366,0.689,0.347,0.661,0.175,0.795,0.255
+            coordinates: 0.85,0.366,0.781,0.35,0.734,0.222,0.795,0.255
             objects: [car, dog, person]
         review:
           alerts:
+            labels: [person, car]
             required_zones:
               - driveway_entrance
         objects:

docs/changelog.d/fix-frigate-detect-fps.bugfix.md

@@ -0,0 +1 @@
+Cap detect FPS to 2 and sync motion masks/zones from live config