fix: 第二轮修复 — 数据库启动检查、会话持久化、URL路由、设备排序等

1. DevTools 启动前检查数据库状态，失败时自动尝试启动
2. ai-core 添加数据库断线重连机制 (30秒间隔)
3. Dashboard 添加数据库状态卡片 (启动/停止/重启)
4. Gateway 会话空闲超时管理 (30分钟标记空闲)
5. 会话/消息 PostgreSQL 持久化 (SessionStore + REST API)
6. 前端服务端会话持久化 + URL hash 路由 + 侧边栏管理
7. 管理员回到主对话按钮
8. IoT 设备卡片固定排序
9. 更新相关文档

frontend/web/src/components/layout/Sidebar.tsx

@@ -1,6 +1,8 @@
+import { useState, useCallback } from 'react';
 import { useSession } from '@/hooks/useSession';
 import { useSessionStore } from '@/store/sessionStore';
 import { CyreneAvatar } from '@/components/persona/CyreneAvatar';
+import type { Session } from '@/types/session';
 
 interface SidebarProps {
   onClose?: () => void;
@@ -11,12 +13,25 @@ export function Sidebar({ onClose }: SidebarProps) {
     sessions,
     createSession,
     deleteSession,
+    deleteAllSessions,
+    clearMainSession,
     setCurrentSession,
+    isAdmin,
   } = useSession();
   const currentSessionId = useSessionStore((s) => s.currentSessionId);
 
-  const displaySessions = sessions;
-  const activeSessionId = currentSessionId;
+  // 确认弹窗状态
+  const [confirmAction, setConfirmAction] = useState<{
+    type: 'delete' | 'clearMain' | 'deleteAll';
+    sessionId?: string;
+  } | null>(null);
+
+  // 按 updated_at 降序排列
+  const displaySessions = [...sessions].sort((a, b) => {
+    const ta = typeof a.updated_at === 'string' ? parseInt(a.updated_at, 10) : (a.updated_at as unknown as number);
+    const tb = typeof b.updated_at === 'string' ? parseInt(b.updated_at, 10) : (b.updated_at as unknown as number);
+    return (tb || 0) - (ta || 0);
+  });
 
   const handleNewChat = async () => {
     const session = await createSession();
@@ -28,11 +43,43 @@ export function Sidebar({ onClose }: SidebarProps) {
     if (onClose) onClose();
   };
 
-  const handleDeleteSession = (e: { stopPropagation: () => void }, id: string) => {
-    e.stopPropagation();
-    deleteSession(id);
+  const handleMainSession = async () => {
+    // 找到主对话
+    const mainSession = displaySessions.find((s) => s.is_main);
+    if (mainSession) {
+      setCurrentSession(mainSession.id);
+      if (onClose) onClose();
+    }
   };
 
+  const handleDeleteClick = (e: React.MouseEvent, id: string) => {
+    e.stopPropagation();
+    const session = displaySessions.find((s) => s.id === id);
+    // 管理员主对话不可删除
+    if (isAdmin && session?.is_main) return;
+    setConfirmAction({ type: 'delete', sessionId: id });
+  };
+
+  const handleConfirmAction = async () => {
+    if (!confirmAction) return;
+    switch (confirmAction.type) {
+      case 'delete':
+        if (confirmAction.sessionId) {
+          await deleteSession(confirmAction.sessionId);
+        }
+        break;
+      case 'clearMain':
+        await clearMainSession();
+        break;
+      case 'deleteAll':
+        await deleteAllSessions();
+        break;
+    }
+    setConfirmAction(null);
+  };
+
+  const cancelConfirm = () => setConfirmAction(null);
+
   /** 格式化时间戳为可读字符串 */
   const formatTime = (ts: string | number): string => {
     if (!ts) return '';
@@ -52,7 +99,28 @@ export function Sidebar({ onClose }: SidebarProps) {
 
   return (
     <aside className="h-full bg-white/90 dark:bg-gray-900/90 border-r border-pink-100 dark:border-pink-900 flex flex-col">
-      {/* 侧边栏头部 */}
+      {/* 主对话按钮 (仅管理员可见) */}
+      {isAdmin && (
+        <div className="p-3 border-b border-pink-100 dark:border-pink-900 flex gap-2">
+          <button
+            onClick={handleMainSession}
+            className="flex-1 flex items-center justify-center gap-1.5 px-3 py-2 bg-amber-50 hover:bg-amber-100 dark:bg-amber-900/20 dark:hover:bg-amber-900/30 text-amber-600 dark:text-amber-400 rounded-xl text-sm font-medium transition-colors border border-amber-200 dark:border-amber-800"
+            title="回到主对话"
+          >
+            <span>🏠</span>
+            <span>主对话</span>
+          </button>
+          <button
+            onClick={() => setConfirmAction({ type: 'clearMain' })}
+            className="flex items-center justify-center px-2 py-2 bg-red-50 hover:bg-red-100 dark:bg-red-900/20 dark:hover:bg-red-900/30 text-red-400 hover:text-red-500 rounded-xl text-sm transition-colors border border-red-200 dark:border-red-800"
+            title="清空主对话消息"
+          >
+            <span>🗑️</span>
+          </button>
+        </div>
+      )}
+
+      {/* 新对话按钮 */}
       <div className="p-4 border-b border-pink-100 dark:border-pink-900">
         <button
           onClick={handleNewChat}
@@ -70,46 +138,80 @@ export function Sidebar({ onClose }: SidebarProps) {
             还没有对话哦，开始和昔涟聊天吧 ♪
           </p>
         ) : (
-          displaySessions.map((session) => (
-            <div
-              key={session.id}
-              onClick={() => handleSelectSession(session.id)}
-              className={`
-                group flex items-center justify-between px-4 py-2.5 mx-2 rounded-lg cursor-pointer transition-colors
-                ${
-                  activeSessionId === session.id
-                    ? 'bg-pink-50 dark:bg-pink-900/30 text-pink-600'
-                    : 'hover:bg-gray-50 dark:hover:bg-gray-800 text-gray-600 dark:text-gray-300'
-                }
-              `}
-            >
-              <div className="flex items-center gap-2 min-w-0 flex-1">
-                <CyreneAvatar size="sm" />
-                <div className="min-w-0">
-                  <p className="text-sm font-medium truncate">{session.title || '新的对话'}</p>
-                  <p className="text-xs text-gray-400 truncate">
-                    {session.message_count != null ? `${session.message_count} 条消息` : ''}
-                    {session.updated_at ? ` · ${formatTime(session.updated_at)}` : ''}
-                  </p>
-                </div>
-              </div>
-              <button
-                onClick={(e) => handleDeleteSession(e, session.id)}
-                className="opacity-0 group-hover:opacity-100 p-1 text-gray-400 hover:text-red-400 transition-all"
-                title="删除会话"
+          displaySessions.map((session) => {
+            const isMainSession = session.is_main;
+            const isActive = currentSessionId === session.id;
+            // 管理员主对话不可删除
+            const canDelete = !(isAdmin && isMainSession);
+
+            return (
+              <div
+                key={session.id}
+                onClick={() => handleSelectSession(session.id)}
+                className={`
+                  group flex items-center justify-between px-4 py-2.5 mx-2 rounded-lg cursor-pointer transition-colors
+                  ${
+                    isActive
+                      ? 'bg-pink-50 dark:bg-pink-900/30 text-pink-600'
+                      : 'hover:bg-gray-50 dark:hover:bg-gray-800 text-gray-600 dark:text-gray-300'
+                  }
+                `}
               >
-                <svg xmlns="http://www.w3.org/2000/svg" className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
-                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
-                </svg>
-              </button>
-            </div>
-          ))
+                <div className="flex items-center gap-2 min-w-0 flex-1">
+                  <CyreneAvatar size="sm" />
+                  <div className="min-w-0">
+                    <p className="text-sm font-medium truncate">
+                      {isMainSession ? '🏠 ' : ''}
+                      {session.title || '新的对话'}
+                    </p>
+                    <p className="text-xs text-gray-400 truncate">
+                      {session.message_count != null
+                        ? `${session.message_count} 条消息`
+                        : ''}
+                      {session.updated_at
+                        ? `${session.message_count != null ? ' · ' : ''}${formatTime(session.updated_at)}`
+                        : ''}
+                    </p>
+                  </div>
+                </div>
+                {canDelete && (
+                  <button
+                    onClick={(e) => handleDeleteClick(e, session.id)}
+                    className="opacity-0 group-hover:opacity-100 p-1 text-gray-400 hover:text-red-400 transition-all"
+                    title="删除会话"
+                  >
+                    <svg
+                      xmlns="http://www.w3.org/2000/svg"
+                      className="h-4 w-4"
+                      fill="none"
+                      viewBox="0 0 24 24"
+                      stroke="currentColor"
+                    >
+                      <path
+                        strokeLinecap="round"
+                        strokeLinejoin="round"
+                        strokeWidth={2}
+                        d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16"
+                      />
+                    </svg>
+                  </button>
+                )}
+              </div>
+            );
+          })
         )}
       </div>
 
-      {/* 底部信息 */}
-      <div className="p-4 border-t border-pink-100 dark:border-pink-900">
-        <div className="flex items-center gap-2 text-xs text-gray-400">
+      {/* 底部：一键清空所有对话 */}
+      <div className="p-3 border-t border-pink-100 dark:border-pink-900">
+        <button
+          onClick={() => setConfirmAction({ type: 'deleteAll' })}
+          className="w-full flex items-center justify-center gap-1.5 px-3 py-2 bg-red-50 hover:bg-red-100 dark:bg-red-900/20 dark:hover:bg-red-900/30 text-red-400 hover:text-red-500 rounded-xl text-xs font-medium transition-colors border border-red-200 dark:border-red-800"
+        >
+          <span>🗑️</span>
+          <span>清空所有对话</span>
+        </button>
+        <div className="flex items-center gap-2 mt-3 text-xs text-gray-400">
           <CyreneAvatar size="sm" />
           <div>
             <p className="font-medium text-pink-400">昔涟 AI</p>
@@ -117,6 +219,42 @@ export function Sidebar({ onClose }: SidebarProps) {
           </div>
         </div>
       </div>
+
+      {/* 确认弹窗 */}
+      {confirmAction && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/40">
+          <div className="bg-white dark:bg-gray-800 rounded-2xl shadow-xl p-6 m-4 max-w-sm w-full border border-pink-100 dark:border-pink-700">
+            <h3 className="text-lg font-semibold text-gray-800 dark:text-gray-200 mb-2">
+              {confirmAction.type === 'delete'
+                ? '删除会话'
+                : confirmAction.type === 'clearMain'
+                  ? '清空主对话'
+                  : '清空所有对话'}
+            </h3>
+            <p className="text-sm text-gray-500 dark:text-gray-400 mb-6">
+              {confirmAction.type === 'delete'
+                ? '确定要删除这个会话吗？此操作不会删除记忆。'
+                : confirmAction.type === 'clearMain'
+                  ? '确定要清空主对话的所有消息吗？此操作不会删除记忆。'
+                  : '确定要删除所有对话吗？此操作不会删除记忆。管理员将回到主对话，普通用户进入新对话。'}
+            </p>
+            <div className="flex justify-end gap-3">
+              <button
+                onClick={cancelConfirm}
+                className="px-4 py-2 rounded-lg text-sm text-gray-500 hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors"
+              >
+                取消
+              </button>
+              <button
+                onClick={handleConfirmAction}
+                className="px-4 py-2 rounded-lg text-sm bg-red-400 hover:bg-red-500 text-white font-medium transition-colors"
+              >
+                确定
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </aside>
   );
 }