fix: topic_id 穿透到 ToolContext，统一 todo scope_key 计算

- AgentBuildRequest 加 topic_id 字段
- Session.create_agent 传入 current_topic
- ToolContext.topic_id 不再硬编码 None
- 删除已废弃的 intercept_todo_write_results
- 工具/emitter/handler 三处 scope_key 计算全部统一

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/gateway/agent_factory.rs

@@ -24,6 +24,8 @@ pub(crate) struct AgentBuildRequest<'a> {
     pub(crate) sender_id: Option<&'a str>,
     pub(crate) message_id: Option<&'a str>,
     pub(crate) provider_config: LLMProviderConfig,
+    /// 当前话题 ID（可选）：用于 todo 等按 topic 隔离的工具
+    pub(crate) topic_id: Option<String>,
     /// 取消信号接收端（可选）：Agent 在每次迭代时检查是否被取消
     pub(crate) cancel_token: Option<tokio::sync::watch::Receiver<()>>,
 }
@@ -73,7 +75,7 @@ impl AgentFactory {
                 sender_id: request.sender_id.map(str::to_string),
                 chat_id: Some(tool_chat_id.to_string()),
                 session_id: Some(session_id),
-                topic_id: None,
+                topic_id: request.topic_id.clone(),
                 message_id: request.message_id.map(str::to_string),
                 message_seq: None,
                 subagent_description: None,

src/gateway/session.rs

@@ -445,89 +445,6 @@ impl Session {
         let _ = self.user_tx.send(msg).await;
     }
 
-    /// 扫描 agent 结果中的 todo_write 工具消息，
-    /// 提取 todos 并做持久化 + 前端推送（同步版本）。
-    pub(crate) fn intercept_todo_write_results(
-        &self,
-        emitted_messages: &[ChatMessage],
-        chat_id: &str,
-    ) {
-        for msg in emitted_messages {
-            if msg.role != "tool" {
-                continue;
-            }
-            if msg.tool_name.as_deref() != Some("todo_write") {
-                continue;
-            }
-
-            // 解析工具返回的 JSON
-            let parsed: serde_json::Value = match serde_json::from_str(&msg.content) {
-                Ok(v) => v,
-                Err(_) => continue,
-            };
-
-            let Some(todos_array) = parsed
-                .get("current_todos")
-                .and_then(|v| v.as_array())
-            else {
-                continue;
-            };
-
-            // 计算持久化所需的 key
-            let session_id = crate::storage::persistent_session_id(&self.channel_name, chat_id);
-            let topic_id = self.current_topic(chat_id);
-            let scope_key = topic_id.map(|t| t.to_string()).unwrap_or_else(|| session_id.clone());
-
-            // 转换为 TodoRecord 并持久化
-            let records: Vec<crate::storage::TodoRecord> = todos_array
-                .iter()
-                .filter_map(|item| {
-                    Some(crate::storage::TodoRecord {
-                        id: item.get("id")?.as_str()?.to_string(),
-                        scope_key: scope_key.clone(),
-                        session_id: session_id.clone(),
-                        topic_id: topic_id.map(|t| t.to_string()),
-                        content: item.get("content")?.as_str()?.to_string(),
-                        status: item.get("status")?.as_str()?.to_string(),
-                        priority: item.get("priority")?.as_str()?.to_string(),
-                        created_at: item.get("created_at")?.as_i64()?,
-                        updated_at: item.get("updated_at")?.as_i64()?,
-                    })
-                })
-                .collect();
-
-            // 持久化到 SQLite
-            tracing::info!(
-                scope_key = %scope_key,
-                todo_count = records.len(),
-                "intercept_todo_write_results: persisting todos"
-            );
-            if let Err(e) = self.store.replace_todos(&scope_key, &records) {
-                tracing::warn!(error = %e, scope_key = %scope_key, "Failed to persist todo list");
-            }
-
-            // 推送到前端（使用 try_send 避免异步）
-            let summaries: Vec<crate::protocol::TodoItemSummary> = records
-                .iter()
-                .map(|r| crate::protocol::TodoItemSummary {
-                    id: r.id.clone(),
-                    content: r.content.clone(),
-                    status: r.status.clone(),
-                    priority: r.priority.clone(),
-                    created_at: r.created_at,
-                    updated_at: r.updated_at,
-                })
-                .collect();
-
-            let _ = self.user_tx.try_send(crate::protocol::WsOutbound::TodoList {
-                todos: summaries,
-                scope_key: scope_key.clone(),
-            });
-
-            break; // 只处理第一个成功的 todo_write
-        }
-    }
-
     /// 获取 provider_config 引用
     pub fn provider_config(&self) -> &LLMProviderConfig {
         &self.provider_config
@@ -604,9 +521,11 @@ impl Session {
     ) -> Result<AgentLoop, AgentError> {
         // 消费 pending 的取消信号接收端（如果存在）
         let cancel_token = self.pending_cancel_tokens.remove(session_chat_id);
+        let topic_id = self.current_topic(session_chat_id).map(|s| s.to_string());
         self.agent_factory.create(AgentBuildRequest {
             channel_name: &self.channel_name,
             session_chat_id,
+            topic_id,
             notification_chat_id,
             sender_id,
             message_id,