fix: 补齐知识库元数据管理与生命周期校验

ai_knowledge_base_v2/apps/backend/app/models/knowledge.py

@@ -12,6 +12,7 @@ PRIMARY_KEY_TYPE = BigInteger().with_variant(Integer, "sqlite")
 
 class Knowledge(Base, TimestampMixin):
     __tablename__ = "sys_knowledge"
+    __table_args__ = (UniqueConstraint("feishu_space_id", "feishu_node_id", name="uq_knowledge_feishu_node"),)
 
     id: Mapped[int] = mapped_column(PRIMARY_KEY_TYPE, primary_key=True, autoincrement=True)
     name: Mapped[str] = mapped_column(String(100), nullable=False)