Integrate PlateRecognizer API as primary ANPR engine

Adds call_platerecognizer() to lpr.py which sends frames to the
PlateRecognizer cloud API (regions=fr) with a 1920px cap to stay
within API limits. In watcher.py, switches to a two-pass frame
scoring strategy: Laplacian sharpness on all frames first, then
YOLO only on the top-10 sharpest frames, then PlateRecognizer on
the top-3 by score. Falls back to local YOLO+Tesseract/PaddleOCR
if the API returns no result.

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

docker-compose.yml

@@ -19,6 +19,7 @@ services:
       - CAPTURE_DURATION=15
       - CAPTURE_FPS=5
       - COOLDOWN=60
+      - PLATERECOGNIZER_API_KEY=c1127284b5ef06b49ade33f1dfc0f50169b88c1d
     labels:
       - traefik.enable=true
       - traefik.http.routers.camwatch.rule=Host(`camwatch.nas.percolouco.com`)