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.

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"
     />