Add label whitelist to filter detection types

DETECTION_LABELS env var accepts comma-separated list (e.g. "person,cat,dog").
Only matching detections are reported; others are ignored. Empty = report all.

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

server/motion.py

@@ -61,6 +61,7 @@ class MotionDetector:
         detection_labels_path: Optional[str] = None,
         detection_confidence: float = 0.5,
         detection_suppress_empty: bool = True,
+        detection_labels: Optional[str] = None,
     ):
         self.camera_id = camera_id
         self.collector_url = collector_url
@@ -82,10 +83,14 @@ class MotionDetector:
         if detection_enabled and detection_model_path:
             try:
                 from detector import ObjectDetector
+                label_whitelist = None
+                if detection_labels:
+                    label_whitelist = set(l.strip() for l in detection_labels.split(","))
                 self._detector = ObjectDetector(
                     model_path=detection_model_path,
                     labels_path=detection_labels_path or "",
                     confidence_threshold=detection_confidence,
+                    label_whitelist=label_whitelist,
                 )
                 logger.info(f"Object detection enabled (model: {detection_model_path})")
             except ImportError as e: