feat: 添加确保会话存在的功能，优化子智能体会话管理

src/storage/mod.rs

@@ -269,12 +269,22 @@ impl SessionStore {
         chat_id: &str,
     ) -> Result<SessionRecord, StorageError> {
         let session_id = persistent_session_id(channel_name, chat_id);
-        if let Some(record) = self.get_session(&session_id)? {
+        self.ensure_session(&session_id, channel_name, chat_id, &format!("{}:{}", channel_name, chat_id))
+    }
+
+    /// 确保指定 session_id 的会话存在（如果不存在则创建）
+    pub fn ensure_session(
+        &self,
+        session_id: &str,
+        channel_name: &str,
+        chat_id: &str,
+        title: &str,
+    ) -> Result<SessionRecord, StorageError> {
+        if let Some(record) = self.get_session(session_id)? {
             return Ok(record);
         }
 
         let now = current_timestamp();
-        let title = format!("{}:{}", channel_name, chat_id);
         let conn = self.conn.lock().expect("session db mutex poisoned");
         conn.execute(
             "
@@ -288,7 +298,7 @@ impl SessionStore {
         )?;
         drop(conn);
 
-        self.get_session(&session_id)?
+        self.get_session(session_id)?
             .ok_or_else(|| rusqlite::Error::QueryReturnedNoRows.into())
     }
 

src/storage/ports.rs

@@ -11,6 +11,15 @@ pub trait ConversationRepository: Send + Sync + 'static {
         chat_id: &str,
     ) -> Result<SessionRecord, StorageError>;
 
+    /// 确保指定 session_id 的会话存在（如果不存在则创建）
+    fn ensure_session(
+        &self,
+        session_id: &str,
+        channel_name: &str,
+        chat_id: &str,
+        title: &str,
+    ) -> Result<SessionRecord, StorageError>;
+
     fn load_messages(&self, session_id: &str) -> Result<Vec<ChatMessage>, StorageError>;
 
     fn append_message(&self, session_id: &str, message: &ChatMessage) -> Result<(), StorageError>;
@@ -139,6 +148,16 @@ impl ConversationRepository for super::SessionStore {
         super::SessionStore::ensure_channel_session(self, channel_name, chat_id)
     }
 
+    fn ensure_session(
+        &self,
+        session_id: &str,
+        channel_name: &str,
+        chat_id: &str,
+        title: &str,
+    ) -> Result<SessionRecord, StorageError> {
+        super::SessionStore::ensure_session(self, session_id, channel_name, chat_id, title)
+    }
+
     fn load_messages(&self, session_id: &str) -> Result<Vec<ChatMessage>, StorageError> {
         super::SessionStore::load_messages(self, session_id)
     }

src/tools/task/runtime.rs

@@ -290,7 +290,18 @@ impl SubAgentRuntime for DefaultSubAgentRuntime {
             task.subagent_type,
         );
 
-        // 3. 保存会话
+        // 3. 在 sessions 表中创建子智能体会话（确保外键约束满足）
+        let session_title = format!("Subagent: {}", task.description);
+        if let Err(e) = self.conversation_repository.ensure_session(
+            &session.session_id,
+            &session.parent_channel_name,
+            &session.parent_chat_id,
+            &session_title,
+        ) {
+            tracing::warn!(error = %e, session_id = %session.session_id, "Failed to ensure subagent session");
+        }
+
+        // 4. 保存任务会话
         self.task_repository.save_task_session(&session).await?;
 
         // 4. 构建子代理系统提示词
@@ -354,21 +365,32 @@ impl SubAgentRuntime for DefaultSubAgentRuntime {
             return Err(TaskError::InvalidParentSession);
         }
 
-        // 3. 构建恢复提示词
+        // 3. 确保 sessions 表中存在子智能体会话记录
+        let session_title = format!("Subagent: {}", session.description);
+        if let Err(e) = self.conversation_repository.ensure_session(
+            &session.session_id,
+            &session.parent_channel_name,
+            &session.parent_chat_id,
+            &session_title,
+        ) {
+            tracing::warn!(error = %e, session_id = %session.session_id, "Failed to ensure subagent session on resume");
+        }
+
+        // 4. 构建恢复提示词
         let system_prompt = SubagentPromptBuilder::build_resume_prompt(
             &session.description,
             &additional_prompt,
         );
 
-        // 4. 创建子代理
+        // 5. 创建子代理
         let agent = self.create_subagent(&session, system_prompt)?;
 
-        // 5. 使用历史继续执行
+        // 6. 使用历史继续执行
         let result = self
             .execute_task_with_history(agent, &session, additional_prompt)
             .await;
 
-        // 6. 更新会话状态
+        // 7. 更新会话状态
         match result {
             Ok(tool_result) => {
                 let mut session = session;