Initial LinkLog implementation

backend/app/models/user.py

@@ -0,0 +1,16 @@
+from dataclasses import dataclass
+from datetime import datetime
+from typing import Optional
+
+
+@dataclass
+class UserRecord:
+    id: str
+    username: str
+    password_hash: str
+    email: Optional[str] = None
+    avatar_url: Optional[str] = None
+    bio: Optional[str] = None
+    is_admin: bool = False
+    created_at: Optional[datetime] = None
+    updated_at: Optional[datetime] = None