fix: use correct column name (animal_id) in get_event_animals query

The animal_registry table uses animal_id as its primary key, not id.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/animaltrack/web/routes/events.py

@@ -121,12 +121,12 @@ def get_event_animals(db: Any, event_id: str) -> list[dict[str, Any]]:
     """
     rows = db.execute(
         """
-        SELECT ar.id, ar.nickname, s.name as species_name
+        SELECT ar.animal_id, ar.nickname, s.name as species_name
         FROM event_animals ea
-        JOIN animal_registry ar ON ar.id = ea.animal_id
+        JOIN animal_registry ar ON ar.animal_id = ea.animal_id
         JOIN species s ON s.code = ar.species_code
         WHERE ea.event_id = ?
-        ORDER BY ar.nickname NULLS LAST, ar.id
+        ORDER BY ar.nickname NULLS LAST, ar.animal_id
         """,
         (event_id,),
     ).fetchall()