fix: ensure atomic creation of knowledge base with proper cleanup on failure

astrbot/core/knowledge_base/kb_mgr.py

@@ -92,6 +92,8 @@ async def create_kb(
         top_m_final: int | None = None,
     ) -> KBHelper:
         """创建新的知识库实例"""
+        if embedding_provider_id is None:
+            raise ValueError("创建知识库时必须提供embedding_provider_id")
         kb = KnowledgeBase(
             kb_name=kb_name,
             description=description,
@@ -104,21 +106,26 @@ async def create_kb(
             top_k_sparse=top_k_sparse if top_k_sparse is not None else 50,
             top_m_final=top_m_final if top_m_final is not None else 5,
         )
-        async with self.kb_db.get_db() as session:
-            session.add(kb)
-            await session.commit()
-            await session.refresh(kb)
-
-            kb_helper = KBHelper(
-                kb_db=self.kb_db,
-                kb=kb,
-                provider_manager=self.provider_manager,
-                kb_root_dir=FILES_PATH,
-                chunker=CHUNKER,
-            )
-            await kb_helper.initialize()
-        self.kb_insts[kb.kb_id] = kb_helper
-        return kb_helper
+        try:
+            async with self.kb_db.get_db() as session:
+                session.add(kb)
+                await session.flush()
+
+                kb_helper = KBHelper(
+                    kb_db=self.kb_db,
+                    kb=kb,
+                    provider_manager=self.provider_manager,
+                    kb_root_dir=FILES_PATH,
+                    chunker=CHUNKER,
+                )
+                await kb_helper.initialize()
+                await session.commit()
+                self.kb_insts[kb.kb_id] = kb_helper
+                return kb_helper
+        except Exception as e:
+            if "kb_name" in str(e):
+                raise ValueError(f"知识库名称 '{kb_name}' 已存在")
+            raise
 
     async def get_kb(self, kb_id: str) -> KBHelper | None:
         """获取知识库实例"""