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({