feat(engine): 添加运行时上下文支持并重构工具迭代限制

添加 RuntimeContext 类用于捕获模型运行时的日期时间信息，
包括UTC时间、本地时间和时区信息，并在系统提示中显示这些信息。

同时增加最大上下文消息数和工具迭代次数的配置选项，
将验证服务从引擎加载器中移除，并更新相关的数据结构和接口。

BREAKING CHANGE: 移除了验证服务，相关字段被替换为证据状态和接受状态。

- 添加 RuntimeContext 类和相关渲染方法
- 增加 max_context_messages 和 max_tool_iterations 配置
- 移除 ValidationService 相关代码
- 更新消息记录中的验证状态字段
- 添加原始工具调用检测和回退处理

app-instance/frontend/app/(app)/page.tsx

@@ -19,7 +19,7 @@ import {
   uploadFile,
   wsManager,
 } from '@/lib/api';
-import { mergeServerWithPendingUsers, shouldMergePendingUsers } from '@/lib/chat-messages';
+import { mergeServerWithPendingUsers, shouldDisplayChatMessage, shouldMergePendingUsers } from '@/lib/chat-messages';
 import { pickAppText } from '@/lib/i18n/core';
 import { useAppI18n } from '@/lib/i18n/provider';
 import { buildSessionProgressView } from '@/lib/session-progress';
@@ -32,7 +32,7 @@ function isSessionUpdatedEvent(data: WsEvent | Record<string, unknown>): data is
 
 function activeTaskStatusLabel(status: string, locale: 'zh-CN' | 'en-US') {
   if (status === 'needs_revision') return pickAppText(locale, '待修改', 'Needs revision');
-  if (status === 'awaiting_feedback') return pickAppText(locale, '待反馈', 'Awaiting feedback');
+  if (status === 'awaiting_acceptance') return pickAppText(locale, '待验收', 'Awaiting acceptance');
   if (status === 'running') return pickAppText(locale, '进行中', 'Running');
   return pickAppText(locale, '进行中', 'Active');
 }
@@ -157,10 +157,11 @@ export default function ChatPage() {
         setSessionProcess(key, process);
       }
       void loadActiveTask(key);
-      const shouldMergePending = shouldMergePendingUsers(detail.messages, localSnapshot, waitingForReply);
+      const displayMessages = detail.messages.filter(shouldDisplayChatMessage);
+      const shouldMergePending = shouldMergePendingUsers(displayMessages, localSnapshot, waitingForReply);
       const nextMessages = shouldMergePending
-        ? mergeServerWithPendingUsers(detail.messages, localSnapshot)
-        : detail.messages;
+        ? mergeServerWithPendingUsers(displayMessages, localSnapshot)
+        : displayMessages;
       setMessages(nextMessages);
       shouldSnapToLatestRef.current = true;
       const last = nextMessages[nextMessages.length - 1];
@@ -217,15 +218,11 @@ export default function ChatPage() {
       if (data.type === 'status' && data.status === 'thinking') {
         setIsThinking(true);
       } else if (data.type === 'message' && data.role === 'assistant') {
-        const validationResult = data.validation_result ?? data.metadata?.validation_result;
-        const validationStatus = data.validation_status
-          ? data.validation_status
-          : validationResult
-            ? ((validationResult as Record<string, unknown>).accepted === true ? 'passed' : 'failed')
-            : 'unknown';
         setIsThinking(false);
         setIsLoading(false);
-        addMessage({
+        const rawEvidenceStatus = data.evidence_status ?? data.metadata?.evidence_status;
+        const evidenceStatus = rawEvidenceStatus === 'recorded' ? 'recorded' : undefined;
+        const assistantMessage = {
           role: 'assistant',
           content: typeof data.content === 'string' ? data.content : '',
           timestamp: new Date().toISOString(),
@@ -233,8 +230,11 @@ export default function ChatPage() {
           run_id: typeof data.run_id === 'string' ? data.run_id : undefined,
           task_id: data.task_id ?? data.metadata?.task_id ?? null,
           task_status: data.task_status ?? data.metadata?.task_status ?? null,
-          validation_status: validationStatus,
-        });
+          evidence_status: evidenceStatus,
+        } as const;
+        if (shouldDisplayChatMessage(assistantMessage)) {
+          addMessage(assistantMessage);
+        }
         void loadSessionMessages(typeof data.session_id === 'string' ? data.session_id : useChatStore.getState().sessionId);
         void loadActiveTask(typeof data.session_id === 'string' ? data.session_id : useChatStore.getState().sessionId);
         loadSessions();
@@ -359,17 +359,18 @@ export default function ChatPage() {
             await loadSessions();
             return;
           }
-          addMessage({
+          const assistantMessage = {
             role: 'assistant',
             content: result.response,
             timestamp: new Date().toISOString(),
             run_id: result.run_id,
             task_id: result.task_id,
             task_status: result.task_status,
-            validation_status: result.validation_result
-              ? (result.validation_result.accepted === true ? 'passed' : 'failed')
-              : 'unknown',
-          });
+            evidence_status: result.evidence_status === 'recorded' ? 'recorded' : undefined,
+          } as const;
+          if (shouldDisplayChatMessage(assistantMessage)) {
+            addMessage(assistantMessage);
+          }
           void getSessionProcess(sessionId).then((process) => setSessionProcess(sessionId, process)).catch(() => null);
           void loadActiveTask(sessionId);
           loadSessions();
@@ -393,7 +394,7 @@ export default function ChatPage() {
     }
   }, [addMessage, clearInputDraft, input, isLoading, loadActiveTask, loadSessionMessages, loadSessions, locale, pendingFiles, revisionTargetRunId, sessionId, setIsLoading, setIsThinking, setSessionProcess, thinkingModeEnabled, updateMessageFeedback]);
 
-  const handleFeedback = useCallback(async (runId: string, feedbackType: 'satisfied' | 'revise' | 'abandon', comment?: string) => {
+  const handleFeedback = useCallback(async (runId: string, feedbackType: 'accept' | 'revise' | 'abandon', comment?: string) => {
     updateMessageFeedback(runId, feedbackType);
     try {
       await submitChatFeedback({

app-instance/frontend/app/(app)/skills/page.tsx

@@ -1238,7 +1238,7 @@ function riskLabel(risk: string, t: (zh: string, en: string) => string): string
 
 function triggerReasonLabel(reason: string, t: (zh: string, en: string) => string): string {
   const labels: Record<string, string> = {
-    validation_accepted_and_user_satisfied: t('任务验证通过且用户满意', 'Validation accepted and user satisfied'),
+    task_accepted: t('任务已接受', 'Task accepted'),
   };
   return labels[reason] || reason;
 }

app-instance/frontend/app/(app)/tasks/[taskId]/page.tsx

@@ -3,7 +3,7 @@
 import Link from 'next/link';
 import { useParams, useRouter } from 'next/navigation';
 import React, { useMemo, useState } from 'react';
-import { AlertCircle, ArrowLeft, Bot, CheckCircle2, Download, FileText, HelpCircle, Loader2, MessageSquare, RefreshCw, ThumbsUp, Trash2, User, XCircle } from 'lucide-react';
+import { AlertCircle, ArrowLeft, Bot, CheckCircle2, Download, FileText, Loader2, MessageSquare, RefreshCw, ThumbsUp, Trash2, User, XCircle } from 'lucide-react';
 
 import { TaskRuntimeStatusBadge, formatTaskRuntimeDuration, formatTaskRuntimeTime, progressPercent } from '@/components/task-runtime/TaskRuntimeShared';
 import { Badge } from '@/components/ui/badge';
@@ -17,8 +17,9 @@ import { buildTaskRuntimeView, type TaskRuntimeNodeView } from '@/lib/task-runti
 import { useChatStore } from '@/lib/store';
 import type { BackendTask, BackendTaskRun, ProcessArtifact, ProcessEvent, ProcessRun } from '@/types';
 
-type TaskFeedbackType = 'satisfied' | 'revise' | 'abandon';
+type TaskFeedbackType = 'accept' | 'revise' | 'abandon';
 type TaskFeedbackItem = {
+  acceptance_type?: unknown;
   feedback_type?: unknown;
   comment?: unknown;
   created_at?: unknown;
@@ -151,12 +152,6 @@ export default function TaskDetailPage() {
   const backendFeedbackRunId = backendTask ? pickFeedbackRunId(backendTask) : null;
 
   if (!task && backendTask) {
-    const validation = backendTask.validation_result;
-    const accepted = Boolean(validation?.accepted);
-    const validationIssues = [
-      ...arrayOfStrings(validation?.issues),
-      ...arrayOfStrings(validation?.missing_requirements),
-    ];
     const feedbackItems = backendTask.feedback || [];
     return (
       <div className="mx-auto max-w-5xl space-y-6 p-6">
@@ -232,57 +227,6 @@ export default function TaskDetailPage() {
           </CardContent>
         </Card>
 
-        <Card>
-          <CardHeader>
-            <CardTitle className="text-base">{pickAppText(locale, '验证和反馈', 'Validation and feedback')}</CardTitle>
-          </CardHeader>
-          <CardContent className="space-y-4 text-sm">
-            <div className="rounded-lg border border-border bg-muted/25 p-4">
-              <div className="flex items-center gap-2">
-                {validation ? (
-                  accepted ? <CheckCircle2 className="h-5 w-5 text-[#657162]" /> : <XCircle className="h-5 w-5 text-destructive" />
-                ) : (
-                  <HelpCircle className="h-5 w-5 text-muted-foreground" />
-                )}
-                <div className="font-medium">
-                  {validation
-                    ? accepted
-                      ? pickAppText(locale, '验证通过', 'Validation passed')
-                      : pickAppText(locale, '需要继续修改', 'Needs revision')
-                    : pickAppText(locale, '尚未验证', 'Not validated yet')}
-                </div>
-              </div>
-              {validation ? (
-                <div className="mt-2 text-muted-foreground">
-                  {pickAppText(locale, '评分', 'Score')}: {String(validation.score ?? '-')} · {pickAppText(locale, '验证器', 'Validator')}: {String(validation.validator ?? '-')}
-                </div>
-              ) : null}
-              {validationIssues.length > 0 && (
-                <ul className="mt-3 list-disc space-y-1 pl-5 text-muted-foreground">
-                  {validationIssues.map((item, index) => <li key={`${item}:${index}`}>{item}</li>)}
-                </ul>
-              )}
-              {typeof validation?.recommended_revision_prompt === 'string' && validation.recommended_revision_prompt && (
-                <p className="mt-3 rounded-md bg-background p-3 text-muted-foreground">{validation.recommended_revision_prompt}</p>
-              )}
-            </div>
-
-            <div className="space-y-2">
-              <div className="font-medium">{pickAppText(locale, '用户反馈', 'User feedback')}</div>
-              {feedbackItems.length === 0 ? (
-                <p className="text-muted-foreground">{pickAppText(locale, '还没有用户反馈。', 'No user feedback yet.')}</p>
-              ) : (
-                feedbackItems.map((item, index) => (
-                  <div key={index} className="rounded-md border border-border p-3">
-                    <div className="font-medium">{humanFeedback(String(item.feedback_type || ''), locale)}</div>
-                    {item.comment ? <p className="mt-1 text-muted-foreground">{String(item.comment)}</p> : null}
-                    {item.created_at ? <p className="mt-1 text-xs text-muted-foreground">{formatTaskRuntimeTime(String(item.created_at), locale)}</p> : null}
-                  </div>
-                ))
-              )}
-            </div>
-          </CardContent>
-        </Card>
       </div>
     );
   }
@@ -476,6 +420,7 @@ export default function TaskDetailPage() {
                   comment,
                 });
                 setRuntimeFeedback({
+                  acceptance_type: feedbackType,
                   feedback_type: feedbackType,
                   comment: comment || '',
                   created_at: new Date().toISOString(),
@@ -660,14 +605,14 @@ function TaskFeedbackPanel({
   return (
     <Card>
       <CardHeader>
-        <CardTitle className="text-base">{pickAppText(locale, '任务反馈', 'Task feedback')}</CardTitle>
+          <CardTitle className="text-base">{pickAppText(locale, '任务验收', 'Task acceptance')}</CardTitle>
       </CardHeader>
       <CardContent className="space-y-4">
         {recordedFeedback ? (
           <div className="rounded-md border border-border bg-muted/25 p-3 text-sm">
             <div className="flex items-center gap-2 font-medium">
               <CheckCircle2 className="h-4 w-4 text-[#657162]" />
-              {pickAppText(locale, '已提交反馈', 'Feedback submitted')}: {humanFeedback(String(recordedFeedback.feedback_type || ''), locale)}
+              {pickAppText(locale, '已提交验收', 'Acceptance submitted')}: {humanFeedback(String(recordedFeedback.acceptance_type || recordedFeedback.feedback_type || ''), locale)}
             </div>
             {recordedFeedback.comment ? (
               <p className="mt-2 text-muted-foreground">{String(recordedFeedback.comment)}</p>
@@ -678,22 +623,22 @@ function TaskFeedbackPanel({
           </div>
         ) : isFinalized ? (
           <div className="rounded-md border border-border bg-muted/25 p-3 text-sm text-muted-foreground">
-            {pickAppText(locale, '任务已结束，不能再提交新的反馈。', 'This task is finalized and cannot accept new feedback.')}
+            {pickAppText(locale, '任务已结束，不能再提交新的验收。', 'This task is finalized and cannot accept new acceptance.')}
           </div>
         ) : !runId ? (
           <div className="rounded-md border border-border bg-muted/25 p-3 text-sm text-muted-foreground">
-            {pickAppText(locale, '暂无可反馈的运行记录。', 'No run is available for feedback yet.')}
+            {pickAppText(locale, '暂无可验收的运行记录。', 'No run is available for acceptance yet.')}
           </div>
         ) : null}
 
         <div className="grid gap-2 sm:grid-cols-3">
           <FeedbackButton
-            type="satisfied"
+            type="accept"
             icon={<ThumbsUp className="mr-2 h-4 w-4" />}
-            label={pickAppText(locale, '满意', 'Satisfied')}
+            label={pickAppText(locale, '接受', 'Accept')}
             actionBusy={actionBusy}
             disabled={!canSubmit}
-            onClick={() => submit('satisfied', comment.trim() || undefined)}
+            onClick={() => submit('accept', comment.trim() || undefined)}
           />
           <FeedbackButton
             type="revise"
@@ -717,10 +662,10 @@ function TaskFeedbackPanel({
           value={comment}
           onChange={(event) => setComment(event.target.value)}
           disabled={Boolean(recordedFeedback) || isFinalized || Boolean(actionBusy)}
-          placeholder={pickAppText(locale, '需要修改时写下具体要求；满意或放弃可选填说明。', 'Describe requested changes; notes are optional for satisfied or abandon.')}
+          placeholder={pickAppText(locale, '需要修改时写下具体要求；接受或放弃可选填说明。', 'Describe requested changes; notes are optional for accept or abandon.')}
         />
         <div className="text-xs text-muted-foreground">
-          {pickAppText(locale, '反馈将记录到当前任务运行：', 'Feedback will be recorded on run: ')}
+          {pickAppText(locale, '验收将记录到当前任务运行：', 'Acceptance will be recorded on run: ')}
           <span className="font-mono">{runId || '-'}</span>
           <span className="mx-1">·</span>
           {pickAppText(locale, '会话：', 'Session: ')}
@@ -807,8 +752,7 @@ function humanTaskStatus(status: string, locale: 'zh-CN' | 'en-US') {
   const map: Record<string, [string, string]> = {
     open: ['已创建', 'Open'],
     running: ['执行中', 'Running'],
-    validating: ['验证中', 'Validating'],
-    awaiting_feedback: ['等待反馈', 'Awaiting feedback'],
+    awaiting_acceptance: ['等待验收', 'Awaiting acceptance'],
     needs_revision: ['需要修改', 'Needs revision'],
     closed: ['已完成', 'Closed'],
     abandoned: ['已放弃', 'Abandoned'],
@@ -818,10 +762,10 @@ function humanTaskStatus(status: string, locale: 'zh-CN' | 'en-US') {
 }
 
 function humanFeedback(type: string, locale: 'zh-CN' | 'en-US') {
-  if (type === 'satisfied') return pickAppText(locale, '满意', 'Satisfied');
+  if (type === 'accept' || type === 'satisfied') return pickAppText(locale, '接受', 'Accepted');
   if (type === 'revise') return pickAppText(locale, '请求修改', 'Revision requested');
   if (type === 'abandon') return pickAppText(locale, '放弃任务', 'Abandoned');
-  return type || pickAppText(locale, '反馈', 'Feedback');
+  return type || pickAppText(locale, '验收', 'Acceptance');
 }
 
 function humanFinishReason(reason: string, locale: 'zh-CN' | 'en-US') {
@@ -848,7 +792,3 @@ function feedbackForRun(items: TaskFeedbackItem[], runId: string | null): TaskFe
 function latestFeedback(items: TaskFeedbackItem[]): TaskFeedbackItem | null {
   return [...items].reverse()[0] ?? null;
 }
-
-function arrayOfStrings(value: unknown): string[] {
-  return Array.isArray(value) ? value.map((item) => String(item)).filter(Boolean) : [];
-}

app-instance/frontend/app/(app)/tasks/page.tsx

@@ -142,7 +142,7 @@ function OrdinaryTasks() {
                   </div>
                 </TableCell>
                 <TableCell>
-                  <Badge variant={task.status === 'awaiting_feedback' || task.status === 'closed' ? 'default' : 'secondary'}>
+                  <Badge variant={task.status === 'awaiting_acceptance' || task.status === 'closed' ? 'default' : 'secondary'}>
                     {taskStatusLabel(task.status, locale)}
                   </Badge>
                 </TableCell>
@@ -185,8 +185,7 @@ function taskStatusLabel(status: string, locale: 'zh-CN' | 'en-US') {
   const labels: Record<string, [string, string]> = {
     open: ['已创建', 'Open'],
     running: ['执行中', 'Running'],
-    validating: ['验证中', 'Validating'],
-    awaiting_feedback: ['等待反馈', 'Awaiting feedback'],
+    awaiting_acceptance: ['等待验收', 'Awaiting acceptance'],
     needs_revision: ['需要修改', 'Needs revision'],
     closed: ['已完成', 'Closed'],
     abandoned: ['已放弃', 'Abandoned'],

app-instance/frontend/components/chat-workbench/ChatWorkbench.tsx

@@ -27,7 +27,7 @@ export function ChatWorkbench({
   processArtifacts: ProcessArtifact[];
   selectedRunId: string | null;
   onSelectRun: (runId: string) => void;
-  onFeedback: (runId: string, feedbackType: 'satisfied' | 'revise' | 'abandon', comment?: string) => void;
+  onFeedback: (runId: string, feedbackType: 'accept' | 'revise' | 'abandon', comment?: string) => void;
   onRequestRevision: (runId: string) => void;
 }) {
   return (

app-instance/frontend/components/chat-workbench/MessageList.tsx

@@ -6,7 +6,7 @@ import { Bot, CheckCircle2, ChevronRight, Loader2, Paperclip, RefreshCcw, Thumbs
 
 import type { ChatMessage, ProcessArtifact, ProcessEvent, ProcessRun } from '@/types';
 import { getAccessToken, getFileUrl } from '@/lib/api';
-import { getTaskCardMessageIndexes } from '@/lib/chat-messages';
+import { getTaskCardMessageIndexes, hasVisibleChatContent, normalizedMessageText, shouldDisplayChatMessage } from '@/lib/chat-messages';
 import { AgentTeamBlock } from '@/components/chat-workbench/AgentTeamBlock';
 import { MarkdownContent } from '@/components/chat-workbench/MarkdownContent';
 import { ScrollArea } from '@/components/ui/scroll-area';
@@ -49,19 +49,14 @@ function MessageBubble({
   message: ChatMessage;
   showTaskCard: boolean;
   canSendFeedback: boolean;
-  onFeedback: (runId: string, feedbackType: 'satisfied' | 'revise' | 'abandon', comment?: string) => void;
+  onFeedback: (runId: string, feedbackType: 'accept' | 'revise' | 'abandon', comment?: string) => void;
   onRequestRevision: (runId: string) => void;
 }) {
   const { locale } = useAppI18n();
   const isUser = message.role === 'user';
-  const textContent = typeof message.content === 'string' ? message.content : String(message.content || '');
-  const [feedbackMode, setFeedbackMode] = React.useState<'satisfied' | null>(null);
+  const textContent = normalizedMessageText(message.content);
+  const [feedbackMode, setFeedbackMode] = React.useState<'accept' | null>(null);
   const [feedbackComment, setFeedbackComment] = React.useState('');
-  const validationFailed = message.validation_status === 'failed';
-  const validationDetails =
-    validationFailed
-      ? pickAppText(locale, '详细原因会在任务验证区展示；展开任务可查看验证报告。', 'Detailed reasons are shown in the task validation area. Open the task to inspect the validation report.')
-      : '';
 
   return (
     <div className={`flex gap-3 ${isUser ? 'justify-end' : ''}`}>
@@ -142,22 +137,14 @@ function MessageBubble({
             </div>
           </div>
         )}
-        {!isUser && validationFailed && (
-          <details className="mt-3 rounded-md border border-destructive/30 bg-destructive/5 p-3">
-            <summary className="cursor-pointer text-base font-semibold text-destructive">
-              {pickAppText(locale, '验证失败', 'Validation failed')}
-            </summary>
-            <p className="mt-2 text-xs leading-5 text-muted-foreground">{validationDetails}</p>
-          </details>
-        )}
         {!isUser && (canSendFeedback || message.feedback_state) && message.run_id && (
           <div className="mt-3 space-y-2 border-t border-border/70 pt-3">
             {message.feedback_state ? (
               <div className="flex items-center gap-2 text-xs text-muted-foreground">
                 <CheckCircle2 className="h-3.5 w-3.5" />
                 <span>
-                  {message.feedback_state === 'satisfied'
-                    ? pickAppText(locale, '已标记满意', 'Marked satisfied')
+                  {message.feedback_state === 'accept' || message.feedback_state === 'satisfied'
+                    ? pickAppText(locale, '已接受', 'Accepted')
                     : message.feedback_state === 'revise'
                       ? pickAppText(locale, '已请求修改', 'Revision requested')
                       : pickAppText(locale, '已放弃任务', 'Task abandoned')}
@@ -168,11 +155,11 @@ function MessageBubble({
                 <div className="flex flex-wrap items-center gap-2">
                   <button
                     type="button"
-                    onClick={() => setFeedbackMode('satisfied')}
+                    onClick={() => setFeedbackMode('accept')}
                     className="inline-flex h-8 items-center gap-1 rounded-md border border-border px-3 text-xs text-muted-foreground hover:bg-accent hover:text-foreground"
                   >
                     <ThumbsUp className="h-3.5 w-3.5" />
-                    {pickAppText(locale, '满意', 'Satisfied')}
+                    {pickAppText(locale, '接受', 'Accept')}
                   </button>
                   <button
                     type="button"
@@ -222,13 +209,6 @@ function MessageBubble({
                 )}
               </>
             )}
-            {message.validation_status && message.validation_status !== 'unknown' && (
-              <span className="text-xs text-muted-foreground">
-                {message.validation_status === 'passed'
-                  ? pickAppText(locale, '验证通过', 'Validated')
-                  : pickAppText(locale, '验证未通过', 'Validation failed')}
-              </span>
-            )}
             {message.feedback_error && (
               <span className="text-xs text-destructive">{message.feedback_error}</span>
             )}
@@ -264,6 +244,17 @@ function shouldHideSystemAgentMessage(message: ChatMessage): boolean {
   );
 }
 
+function hasRenderableMessageContent(message: ChatMessage): boolean {
+  return hasVisibleChatContent(message);
+}
+
+function shouldHideMessage(message: ChatMessage): boolean {
+  if (shouldHideSystemAgentMessage(message)) {
+    return true;
+  }
+  return !shouldDisplayChatMessage(message);
+}
+
 function parseTimelineTime(value?: string | null): number | null {
   if (!value) return null;
   const parsed = new Date(value).getTime();
@@ -342,12 +333,12 @@ export function MessageList({
   processArtifacts: ProcessArtifact[];
   selectedRunId: string | null;
   onSelectRun: (runId: string) => void;
-  onFeedback: (runId: string, feedbackType: 'satisfied' | 'revise' | 'abandon', comment?: string) => void;
+  onFeedback: (runId: string, feedbackType: 'accept' | 'revise' | 'abandon', comment?: string) => void;
   onRequestRevision: (runId: string) => void;
 }) {
   const { locale } = useAppI18n();
   const visibleMessages = React.useMemo(
-    () => messages.filter((message) => !shouldHideSystemAgentMessage(message)),
+    () => messages.filter((message) => !shouldHideMessage(message)),
     [messages]
   );
   const teamGroups = React.useMemo(
@@ -385,14 +376,21 @@ export function MessageList({
     () => getTaskCardMessageIndexes(visibleMessages),
     [visibleMessages]
   );
-  const latestFeedbackRunId = [...visibleMessages]
-    .reverse()
-    .find((message) =>
-      message.role === 'assistant'
-      && message.run_id
-      && message.task_id
-      && message.task_status === 'awaiting_feedback'
-    )?.run_id;
+  const latestFeedbackMessageIndex = (() => {
+    for (let index = visibleMessages.length - 1; index >= 0; index -= 1) {
+      const message = visibleMessages[index];
+      if (
+        message.role === 'assistant'
+        && message.run_id
+        && message.task_id
+        && message.task_status === 'awaiting_acceptance'
+        && hasRenderableMessageContent(message)
+      ) {
+        return index;
+      }
+    }
+    return -1;
+  })();
 
   return (
     <ScrollArea className="h-full px-8" viewportRef={viewportRef}>
@@ -411,7 +409,7 @@ export function MessageList({
               key={item.key}
               message={item.message}
               showTaskCard={taskCardMessageIndexes.has(item.messageIndex)}
-              canSendFeedback={Boolean(latestFeedbackRunId && item.message.run_id === latestFeedbackRunId)}
+              canSendFeedback={item.messageIndex === latestFeedbackMessageIndex}
               onFeedback={onFeedback}
               onRequestRevision={onRequestRevision}
             />

app-instance/frontend/lib/api.ts

@@ -271,7 +271,7 @@ export async function sendMessage(
   run_id?: string;
   task_id?: string | null;
   task_status?: string | null;
-  validation_result?: Record<string, unknown> | null;
+  evidence_status?: string | null;
 }> {
   const body: Record<string, unknown> = { message, session_id: sessionId };
   if (attachments && attachments.length > 0) {
@@ -293,7 +293,7 @@ export async function sendMessage(
     finish_reason?: string;
     task_id?: string | null;
     task_status?: string | null;
-    validation_result?: Record<string, unknown> | null;
+    evidence_status?: string | null;
   }>('/api/chat', {
     method: 'POST',
     body: JSON.stringify(body),
@@ -305,28 +305,29 @@ export async function sendMessage(
     run_id: result.run_id,
     task_id: result.task_id,
     task_status: result.task_status,
-    validation_result: result.validation_result,
+    evidence_status: result.evidence_status,
   };
 }
 
 export async function submitChatFeedback(params: {
   sessionId: string;
   runId: string;
-  feedbackType: 'satisfied' | 'revise' | 'abandon';
+  feedbackType: 'accept' | 'revise' | 'abandon';
   comment?: string;
 }): Promise<{
   session_id: string;
   run_id: string;
   task_id: string;
   task_status: string;
+  acceptance_type: string;
   feedback_type: string;
 }> {
-  return fetchJSON('/api/chat/feedback', {
+  return fetchJSON('/api/chat/acceptance', {
     method: 'POST',
     body: JSON.stringify({
       session_id: params.sessionId,
       run_id: params.runId,
-      feedback_type: params.feedbackType,
+      acceptance_type: params.feedbackType,
       comment: params.comment,
     }),
   });

app-instance/frontend/lib/chat-messages.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest';
 
-import { getTaskCardMessageIndexes, mergeServerWithPendingUsers, shouldMergePendingUsers } from '@/lib/chat-messages';
+import { getTaskCardMessageIndexes, mergeServerWithPendingUsers, shouldDisplayChatMessage, shouldMergePendingUsers } from '@/lib/chat-messages';
 import type { ChatMessage } from '@/types';
 
 describe('chat message helpers', () => {
@@ -85,10 +85,17 @@ describe('chat message helpers', () => {
         content: 'Final answer.',
         run_id: 'run-1',
         task_id: 'task-1',
-        task_status: 'awaiting_feedback',
+        task_status: 'awaiting_acceptance',
       },
     ];
 
     expect(Array.from(getTaskCardMessageIndexes(messages))).toEqual([2]);
   });
+
+  it('hides empty assistant records from session history', () => {
+    expect(shouldDisplayChatMessage({ role: 'assistant', content: '', task_id: 'task-1', run_id: 'run-1' })).toBe(false);
+    expect(shouldDisplayChatMessage({ role: 'assistant', content: '\u200B\uFEFF', task_id: 'task-1', run_id: 'run-1' })).toBe(false);
+    expect(shouldDisplayChatMessage({ role: 'assistant', content: 'Final answer.', task_id: 'task-1', run_id: 'run-1' })).toBe(true);
+    expect(shouldDisplayChatMessage({ role: 'user', content: '' })).toBe(true);
+  });
 });

app-instance/frontend/lib/chat-messages.ts

@@ -1,5 +1,28 @@
 import type { ChatMessage } from '@/types';
 
+const INVISIBLE_CONTENT_CHARS = /[\u200B-\u200D\uFEFF]/g;
+
+export function normalizedMessageText(content: unknown): string {
+  if (typeof content === 'string') {
+    return content.replace(INVISIBLE_CONTENT_CHARS, '').trim();
+  }
+  if (content == null) {
+    return '';
+  }
+  return String(content).replace(INVISIBLE_CONTENT_CHARS, '').trim();
+}
+
+export function hasVisibleChatContent(msg: ChatMessage): boolean {
+  if (normalizedMessageText(msg.content)) {
+    return true;
+  }
+  return Boolean(msg.attachments?.length);
+}
+
+export function shouldDisplayChatMessage(msg: ChatMessage): boolean {
+  return msg.role !== 'assistant' || hasVisibleChatContent(msg);
+}
+
 export function messageFingerprint(msg: ChatMessage): string {
   const attachmentKey = (msg.attachments ?? [])
     .map((a) => `${a.file_id ?? ''}:${a.name}:${a.content_type}:${a.size ?? ''}`)

app-instance/frontend/types/index.ts

@@ -48,8 +48,9 @@ export interface ChatMessage {
   run_id?: string;
   task_id?: string | null;
   task_status?: string | null;
-  validation_status?: 'passed' | 'failed' | 'unknown';
-  feedback_state?: 'satisfied' | 'revise' | 'abandon';
+  evidence_status?: 'recorded';
+  acceptance_state?: 'accept' | 'revise' | 'abandon';
+  feedback_state?: 'accept' | 'satisfied' | 'revise' | 'abandon';
   feedback_error?: string;
   message_type?: string | null;
   scheduled_job_id?: string | null;
@@ -153,6 +154,7 @@ export interface SystemStatus {
   workspace_exists: boolean;
   model: string;
   max_tokens: number;
+  max_context_messages?: number;
   temperature: number;
   max_tool_iterations: number;
   providers: ProviderStatus[];
@@ -315,6 +317,7 @@ export interface BackendTaskRun {
   attempt_index?: number | null;
   task_text?: string;
   messages: BackendTaskRunMessage[];
+  evidence_status?: string | null;
   validation_result?: Record<string, unknown> | null;
 }
 
@@ -972,12 +975,12 @@ export interface ChatAssistantEvent {
   run_id?: string;
   task_id?: string | null;
   task_status?: string | null;
-  validation_status?: 'passed' | 'failed' | 'unknown';
+  evidence_status?: 'recorded';
   validation_result?: Record<string, unknown> | null;
   metadata?: {
     task_id?: string | null;
     task_status?: string | null;
-    validation_result?: Record<string, unknown> | null;
+    evidence_status?: string | null;
     [key: string]: unknown;
   };
 }