Add wildlife threat classification with size heuristics

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

vigilar/detection/wildlife.py

@@ -0,0 +1,38 @@
+"""Wildlife threat level classification."""
+
+from vigilar.config import WildlifeConfig
+from vigilar.detection.person import Detection
+
+
+def classify_wildlife_threat(
+    detection: Detection,
+    config: WildlifeConfig,
+    frame_area: int,
+) -> tuple[str, str]:
+    """Classify a wildlife detection into threat level and species.
+
+    Returns (threat_level, species_name).
+    """
+    species = detection.class_name
+    threat_map = config.threat_map
+
+    # Direct COCO class mapping first
+    if species in threat_map.predator:
+        return "PREDATOR", species
+    if species in threat_map.nuisance:
+        return "NUISANCE", species
+    if species in threat_map.passive:
+        return "PASSIVE", species
+
+    # Fallback to size heuristics for unknown species
+    _, _, w, h = detection.bbox
+    bbox_area = w * h
+    area_ratio = bbox_area / frame_area if frame_area > 0 else 0
+
+    heuristics = config.size_heuristics
+    if area_ratio < heuristics.small:
+        return "NUISANCE", species
+    elif area_ratio < heuristics.medium:
+        return "PREDATOR", species
+    else:
+        return "PASSIVE", species