第二步

backend/app/models/__init__.py

@@ -0,0 +1,21 @@
+"""SQLAlchemy 2.0 模型包。"""
+
+from app.models.base import Base, generate_uuid, utcnow_iso
+from app.models.plan import Plan
+from app.models.user import User
+from app.models.knowledge_base import KnowledgeBase
+from app.models.document_category import DocumentCategory
+from app.models.document import Document
+from app.models.access_log import AccessLog
+
+__all__ = [
+    "Base",
+    "generate_uuid",
+    "utcnow_iso",
+    "Plan",
+    "User",
+    "KnowledgeBase",
+    "DocumentCategory",
+    "Document",
+    "AccessLog",
+]