Fix minor issues: enum types, backup path, JS URLs, status field, timestamp docs

- CameraConfig.location now uses CameraLocation enum (Pydantic v2 coerces TOML strings)
- Wildlife classifier returns ThreatLevel enum values with correct return type annotation
- Model backup path fixed: pet_id_backup.pt instead of pet_id.backup.pt
- Dashboard submitLabel JS now posts to /pets/<sighting_id>/label matching Flask route
- Pet status API computes status field (safe/unknown) based on last-seen recency
- digest.py comment explains timestamp unit difference between tables

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

vigilar/detection/trainer.py

@@ -122,7 +122,9 @@ class PetTrainer:
                          epoch + 1, epochs, running_loss / len(loader), accuracy)
 
             if self._model_output_path.exists():
-                backup_path = self._model_output_path.with_suffix(".backup.pt")
+                backup_path = self._model_output_path.with_name(
+                    self._model_output_path.stem + "_backup.pt"
+                )
                 shutil.copy2(self._model_output_path, backup_path)
                 log.info("Backed up previous model to %s", backup_path)
 

vigilar/detection/wildlife.py

@@ -1,6 +1,7 @@
 """Wildlife threat level classification."""
 
 from vigilar.config import WildlifeConfig
+from vigilar.constants import ThreatLevel
 from vigilar.detection.person import Detection
 
 
@@ -8,7 +9,7 @@ def classify_wildlife_threat(
     detection: Detection,
     config: WildlifeConfig,
     frame_area: int,
-) -> tuple[str, str]:
+) -> tuple[ThreatLevel, str]:
     """Classify a wildlife detection into threat level and species.
 
     Returns (threat_level, species_name).
@@ -18,11 +19,11 @@ def classify_wildlife_threat(
 
     # Direct COCO class mapping first
     if species in threat_map.predator:
-        return "PREDATOR", species
+        return ThreatLevel.PREDATOR, species
     if species in threat_map.nuisance:
-        return "NUISANCE", species
+        return ThreatLevel.NUISANCE, species
     if species in threat_map.passive:
-        return "PASSIVE", species
+        return ThreatLevel.PASSIVE, species
 
     # Fallback to size heuristics for unknown species
     _, _, w, h = detection.bbox
@@ -31,8 +32,8 @@ def classify_wildlife_threat(
 
     heuristics = config.size_heuristics
     if area_ratio < heuristics.small:
-        return "NUISANCE", species
+        return ThreatLevel.NUISANCE, species
     elif area_ratio < heuristics.medium:
-        return "PREDATOR", species
+        return ThreatLevel.PREDATOR, species
     else:
-        return "PASSIVE", species
+        return ThreatLevel.PASSIVE, species