Differentiate PET_ESCAPE and UNKNOWN_ANIMAL events by zone and identity

Replace the flat pet/detected handler with context-aware classification:
unknown animals (no pet_id) → UNKNOWN_ANIMAL/WARNING, known pets in
exterior/transition zones → PET_ESCAPE/ALERT, known pets indoors →
PET_DETECTED/INFO. Adds four new unit tests covering all three paths.

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

vigilar/events/processor.py

@@ -129,6 +129,15 @@ class EventProcessor:
 
             # Pet detection
             if suffix == "pet/detected":
+                pet_id = payload.get("pet_id")
+                camera_location = payload.get("camera_location", "INTERIOR")
+
+                if not pet_id:
+                    return EventType.UNKNOWN_ANIMAL, Severity.WARNING, camera_id
+
+                if camera_location in ("EXTERIOR", "TRANSITION"):
+                    return EventType.PET_ESCAPE, Severity.ALERT, camera_id
+
                 return EventType.PET_DETECTED, Severity.INFO, camera_id
 
             # Wildlife detection — severity depends on threat_level in payload