refactor: rename canto-backend → backend, canto-frontend → frontend

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

backend/schemas/cache.py

@@ -0,0 +1,15 @@
+from datetime import datetime
+from typing import Optional, Dict, Any
+from pydantic import BaseModel, ConfigDict
+
+class CacheEntry(BaseModel):
+    id: int
+    user_id: int
+    ref_audio_hash: str
+    cache_path: str
+    meta_data: Optional[Dict[str, Any]] = None
+    created_at: datetime
+    last_accessed: datetime
+    access_count: int
+
+    model_config = ConfigDict(from_attributes=True)