feat(admin): Add activity logs page and fix AI chat markdown rendering

- Add paginated activity logs API with filters (date, module, action, keyword)

- Add ActivityLogsPage with table, filters, and detail modal

- Add markdown rendering support for AI chat messages

- Remove prototype placeholder content from chat sidebar

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend-v2/src/modules/aia/components/ChatWorkspace.tsx

@@ -28,6 +28,7 @@ import { ThinkingBlock } from '@/shared/components/Chat';
 import { getAccessToken } from '@/framework/auth/api';
 import { AGENTS, AGENT_PROMPTS, BRAND_COLORS } from '../constants';
 import type { AgentConfig, Conversation, Message } from '../types';
+import { MarkdownContent } from '../protocol-agent/components/MarkdownContent';
 import '../styles/chat-workspace.css';
 
 /**
@@ -651,14 +652,6 @@ export const ChatWorkspace: React.FC<ChatWorkspaceProps> = ({
           </div>
         </div>
 
-        {/* 用户信息 */}
-        <div className="sidebar-user">
-          <div className="user-avatar">U</div>
-          <div className="user-info">
-            <div className="user-name">Dr. Wang</div>
-            <div className="user-plan">专业版会员</div>
-          </div>
-        </div>
       </aside>
 
       {/* 主对话区 */}
@@ -750,7 +743,11 @@ export const ChatWorkspace: React.FC<ChatWorkspaceProps> = ({
                   {/* 消息内容（有内容时才显示气泡） */}
                   {(msg.content || (msg.role === 'assistant' && isStreaming && index === messages.length - 1)) && (
                     <div className={`message-bubble ${msg.role}`}>
-                      {msg.content}
+                      {msg.role === 'assistant' ? (
+                        <MarkdownContent content={msg.content || ''} />
+                      ) : (
+                        msg.content
+                      )}
                       {msg.role === 'assistant' && isStreaming && index === messages.length - 1 && (
                         <span className="typing-cursor">▊</span>
                       )}

frontend-v2/src/modules/aia/styles/chat-workspace.css

@@ -946,3 +946,93 @@
   border-radius: 8px;
 }
 
+/* ============================================ */
+/* MarkdownContent 组件样式 */
+/* ============================================ */
+.message-bubble .markdown-content {
+  white-space: normal;
+}
+
+.message-bubble .markdown-content p {
+  margin: 0 0 8px 0;
+}
+
+.message-bubble .markdown-content p:last-child {
+  margin-bottom: 0;
+}
+
+.message-bubble .markdown-content .md-divider {
+  border: none;
+  border-top: 1px solid #E5E7EB;
+  margin: 12px 0;
+}
+
+.message-bubble .markdown-content h1,
+.message-bubble .markdown-content h2,
+.message-bubble .markdown-content h3 {
+  margin: 16px 0 8px 0;
+  font-weight: 700;
+  line-height: 1.4;
+}
+
+.message-bubble .markdown-content h1:first-child,
+.message-bubble .markdown-content h2:first-child,
+.message-bubble .markdown-content h3:first-child {
+  margin-top: 0;
+}
+
+.message-bubble .markdown-content h1 {
+  font-size: 1.3em;
+}
+
+.message-bubble .markdown-content h2 {
+  font-size: 1.2em;
+}
+
+.message-bubble .markdown-content h3 {
+  font-size: 1.1em;
+}
+
+.message-bubble .markdown-content ul,
+.message-bubble .markdown-content ol {
+  margin: 8px 0 12px 0;
+  padding-left: 24px;
+}
+
+.message-bubble .markdown-content ul {
+  list-style-type: disc;
+}
+
+.message-bubble .markdown-content ol {
+  list-style-type: decimal;
+}
+
+.message-bubble .markdown-content li {
+  margin: 6px 0;
+  line-height: 1.6;
+  display: list-item;
+}
+
+.message-bubble .markdown-content li::marker {
+  color: #4F6EF2;
+}
+
+.message-bubble .markdown-content strong {
+  font-weight: 700;
+  color: #1F2937;
+}
+
+.message-bubble .markdown-content em {
+  font-style: italic;
+  color: #4B5563;
+}
+
+.message-bubble .markdown-content code {
+  background: rgba(79, 110, 242, 0.1);
+  color: #4F6EF2;
+  padding: 2px 6px;
+  border-radius: 4px;
+  font-family: 'Monaco', 'Consolas', 'Courier New', monospace;
+  font-size: 0.9em;
+}
+