feat: add wait_for_approval tool for agent workflow pausing

Allow agent to pause execution at critical decision points and wait
for user confirmation via comments before continuing.

src/agent.rs

@@ -53,6 +53,7 @@ pub fn plan_infos_from_state(state: &AgentState) -> Vec<PlanStepInfo> {
         let status = match s.status {
             StepStatus::Pending => "pending",
             StepStatus::Running => "running",
+            StepStatus::WaitingApproval => "waiting_approval",
             StepStatus::Done => "done",
             StepStatus::Failed => "failed",
         };
@@ -319,7 +320,7 @@ async fn agent_loop(
                 let result = run_agent_loop(
                     &llm, &exec, &pool, &broadcast_tx,
                     &project_id, &workflow_id, &requirement, &workdir, &mgr,
-                    &instructions, None, ext_tools,
+                    &instructions, None, ext_tools, &mut rx,
                 ).await;
 
                 let final_status = if result.is_ok() { "done" } else { "failed" };
@@ -427,7 +428,7 @@ async fn agent_loop(
                     let result = run_agent_loop(
                         &llm, &exec, &pool, &broadcast_tx,
                         &project_id, &workflow_id, &wf.requirement, &workdir, &mgr,
-                        &instructions, Some(state), None,
+                        &instructions, Some(state), None, &mut rx,
                     ).await;
 
                     let final_status = if result.is_ok() { "done" } else { "failed" };
@@ -608,6 +609,13 @@ fn build_execution_tools() -> Vec<Tool> {
             },
             "required": ["content"]
         })),
+        make_tool("wait_for_approval", "暂停执行，等待用户确认后继续。用于关键决策点，如：确认方案、确认配置变更、确认危险操作等。用户的回复会作为反馈返回。", serde_json::json!({
+            "type": "object",
+            "properties": {
+                "reason": { "type": "string", "description": "说明为什么需要用户确认" }
+            },
+            "required": ["reason"]
+        })),
         tool_kb_search(),
         tool_kb_read(),
     ]
@@ -637,6 +645,7 @@ fn build_feedback_prompt(project_id: &str, state: &AgentState, feedback: &str) -
         let status = match s.status {
             StepStatus::Done => " [done]",
             StepStatus::Running => " [running]",
+            StepStatus::WaitingApproval => " [waiting]",
             StepStatus::Failed => " [FAILED]",
             StepStatus::Pending => "",
         };
@@ -982,6 +991,7 @@ async fn run_agent_loop(
     instructions: &str,
     initial_state: Option<AgentState>,
     external_tools: Option<&ExternalToolManager>,
+    event_rx: &mut mpsc::Receiver<AgentEvent>,
 ) -> anyhow::Result<()> {
     let planning_tools = build_planning_tools();
     let mut execution_tools = build_execution_tools();
@@ -1134,6 +1144,64 @@ async fn run_agent_loop(
                         state.current_step_chat_history.push(ChatMessage::tool_result(&tc.id, "Scratchpad 已更新。"));
                     }
 
+                    "wait_for_approval" => {
+                        let reason = args["reason"].as_str().unwrap_or("等待确认");
+
+                        // Mark step as WaitingApproval
+                        if let Some(step) = state.steps.iter_mut().find(|s| s.order == cur) {
+                            step.status = StepStatus::WaitingApproval;
+                        }
+                        let _ = broadcast_tx.send(WsMessage::PlanUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            steps: plan_infos_from_state(&state),
+                        });
+                        let _ = broadcast_tx.send(WsMessage::WorkflowStatusUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            status: "waiting_approval".into(),
+                        });
+                        let _ = sqlx::query("UPDATE workflows SET status = 'waiting_approval' WHERE id = ?")
+                            .bind(workflow_id)
+                            .execute(pool)
+                            .await;
+                        save_state_snapshot(pool, workflow_id, cur, &state).await;
+                        log_execution(pool, broadcast_tx, workflow_id, cur, "wait_for_approval", reason, reason, "waiting").await;
+
+                        tracing::info!("[workflow {}] Waiting for approval: {}", workflow_id, reason);
+
+                        // Block until we receive a Comment event
+                        let approval_content = loop {
+                            match event_rx.recv().await {
+                                Some(AgentEvent::Comment { content, .. }) => break content,
+                                Some(_) => continue,
+                                None => return Err(anyhow::anyhow!("Event channel closed while waiting for approval")),
+                            }
+                        };
+
+                        tracing::info!("[workflow {}] Approval received: {}", workflow_id, approval_content);
+
+                        // Resume: restore Running status
+                        if let Some(step) = state.steps.iter_mut().find(|s| s.order == cur) {
+                            step.status = StepStatus::Running;
+                            step.user_feedbacks.push(approval_content.clone());
+                        }
+                        let _ = sqlx::query("UPDATE workflows SET status = 'executing' WHERE id = ?")
+                            .bind(workflow_id)
+                            .execute(pool)
+                            .await;
+                        let _ = broadcast_tx.send(WsMessage::WorkflowStatusUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            status: "executing".into(),
+                        });
+                        let _ = broadcast_tx.send(WsMessage::PlanUpdate {
+                            workflow_id: workflow_id.to_string(),
+                            steps: plan_infos_from_state(&state),
+                        });
+
+                        state.current_step_chat_history.push(
+                            ChatMessage::tool_result(&tc.id, &format!("用户已确认。反馈: {}", approval_content))
+                        );
+                    }
+
                     "update_requirement" => {
                         let new_req = args["requirement"].as_str().unwrap_or("");
                         let _ = sqlx::query("UPDATE workflows SET requirement = ? WHERE id = ?")

src/state.rs

@@ -19,6 +19,7 @@ pub enum AgentPhase {
 pub enum StepStatus {
     Pending,
     Running,
+    WaitingApproval,
     Done,
     Failed,
 }
@@ -120,7 +121,7 @@ impl AgentState {
     /// 全部 Done 时返回 None。
     pub fn first_actionable_step(&self) -> Option<i32> {
         self.steps.iter()
-            .find(|s| matches!(s.status, StepStatus::Pending | StepStatus::Running))
+            .find(|s| matches!(s.status, StepStatus::Pending | StepStatus::Running | StepStatus::WaitingApproval))
             .map(|s| s.order)
     }
 
@@ -141,6 +142,7 @@ impl AgentState {
             let marker = match s.status {
                 StepStatus::Done => "  done",
                 StepStatus::Running => "  >> current",
+                StepStatus::WaitingApproval => "  ⏳ waiting",
                 StepStatus::Failed => "  FAILED",
                 StepStatus::Pending => "",
             };

web/src/components/CommentSection.vue

@@ -4,6 +4,7 @@ import { ref, nextTick } from 'vue'
 const props = defineProps<{
   disabled?: boolean
   quotes: string[]
+  waitingApproval?: boolean
 }>()
 
 const emit = defineEmits<{
@@ -50,7 +51,10 @@ defineExpose({ focusInput })
 </script>
 
 <template>
-  <div class="comment-section">
+  <div class="comment-section" :class="{ 'waiting-approval': waitingApproval }">
+    <div v-if="waitingApproval" class="approval-banner">
+      ⏳ Agent 正在等待你的确认，请在下方输入反馈后发送
+    </div>
     <div v-if="quotes.length" class="quotes-bar">
       <div v-for="(q, i) in quotes" :key="i" class="quote-chip">
         <span class="quote-text">{{ q.length > 60 ? q.slice(0, 60) + '...' : q }}</span>
@@ -78,6 +82,20 @@ defineExpose({ focusInput })
   overflow: hidden;
 }
 
+.comment-section.waiting-approval {
+  border-color: var(--accent);
+  box-shadow: 0 0 0 1px var(--accent), 0 0 12px rgba(79, 195, 247, 0.15);
+}
+
+.approval-banner {
+  padding: 8px 12px;
+  background: rgba(79, 195, 247, 0.1);
+  color: var(--accent);
+  font-size: 13px;
+  font-weight: 500;
+  border-bottom: 1px solid rgba(79, 195, 247, 0.2);
+}
+
 .quotes-bar {
   display: flex;
   flex-wrap: wrap;

web/src/components/WorkflowView.vue

@@ -198,6 +198,7 @@ async function onSubmitComment(text: string) {
       ref="commentRef"
       :disabled="!workflow"
       :quotes="quotes"
+      :waitingApproval="workflow?.status === 'waiting_approval'"
       @submit="onSubmitComment"
       @removeQuote="removeQuote"
     />