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/store/sessionStore.ts

@@ -1,15 +1,38 @@
 import { create } from 'zustand';
 import type { Session } from '@/types/session';
 import type { Message } from '@/types/chat';
-import { fetchSessionMessages as apiFetchMessages } from '@/api/client';
+import {
+  fetchSessions,
+  fetchMessages,
+  createSession as apiCreateSession,
+  deleteSession as apiDeleteSession,
+  deleteAllSessions as apiDeleteAllSessions,
+  clearSessionMessages as apiClearMessages,
+} from '@/api/sessions';
 import { useChatStore } from '@/store/chatStore';
 
+/** 生成简易随机ID */
+function randomID(n: number = 12): string {
+  const letters = 'abcdefghijklmnopqrstuvwxyz0123456789';
+  let result = '';
+  for (let i = 0; i < n; i++) {
+    result += letters.charAt(Math.floor(Math.random() * letters.length));
+  }
+  return `session_${result}`;
+}
+
+/** 判断是否为管理员用户 (user_id 以 "admin_" 开头) */
+export function isAdminUser(userId: string | null): boolean {
+  return userId?.startsWith('admin_') ?? false;
+}
+
 interface SessionStore {
   sessions: Session[];
   currentSessionId: string | null;
   loading: boolean;
   messages: Message[];
 
+  // 基础操作
   setSessions: (sessions: Session[]) => void;
   addSession: (session: Session) => void;
   removeSession: (id: string) => void;
@@ -17,9 +40,17 @@ interface SessionStore {
   setLoading: (loading: boolean) => void;
   setMessages: (messages: Message[]) => void;
   clearMessages: () => void;
+
+  // 服务端持久化操作
+  loadSessionsFromServer: (userId: string) => Promise<void>;
+  loadMessagesFromServer: (sessionId: string) => Promise<void>;
+  clearMainSessionMessages: (sessionId: string) => Promise<boolean>;
+  deleteSessionAndRefresh: (id: string, userId: string) => Promise<void>;
+  deleteAllSessionsAndReset: (userId: string) => Promise<void>;
+  ensureMainSession: (userId: string) => Promise<Session | null>;
 }
 
-export const useSessionStore = create<SessionStore>((set) => ({
+export const useSessionStore = create<SessionStore>((set, get) => ({
   sessions: [],
   currentSessionId: null,
   loading: false,
@@ -34,46 +65,143 @@ export const useSessionStore = create<SessionStore>((set) => ({
       currentSessionId: state.currentSessionId === id ? null : state.currentSessionId,
       messages: state.currentSessionId === id ? [] : state.messages,
     })),
-  setCurrentSessionId: async (id) => {
-    // 立即清除旧消息，防止闪旧数据
-    set({ currentSessionId: id, messages: [], loading: true });
-    useChatStore.getState().clearMessages();
-
-    // 清除旧消息（同时清 chatStore）
-    if (id === null) {
-      set({ messages: [], loading: false });
-      return;
-    }
-
-    // 从后端加载历史消息
-    try {
-      const resp = await apiFetchMessages(id);
-      if (resp.data) {
-        const data = resp.data as { messages: Message[] };
-        const msgs = (data.messages || []).map((m: Message, i: number) => ({
-          ...m,
-          id: m.id || `hist_${i}_${Date.now()}`,
-        }));
-        set({ messages: msgs, loading: false });
-        // 同步到 chatStore 以便 ChatContainer 渲染
-        useChatStore.getState().setMessages(msgs);
-      } else {
-        set({ messages: [], loading: false });
-        useChatStore.getState().clearMessages();
-      }
-    } catch {
-      set({ messages: [], loading: false });
+  setCurrentSessionId: (id) => {
+    set({ currentSessionId: id });
+    // 切换会话时清空旧消息，等待加载
+    if (id !== get().currentSessionId) {
+      set({ messages: [], loading: true });
       useChatStore.getState().clearMessages();
     }
   },
   setLoading: (loading) => set({ loading }),
   setMessages: (messages) => {
     set({ messages });
-    // 同步到 chatStore
     useChatStore.getState().setMessages(messages);
   },
   clearMessages: () => {
     set({ messages: [] });
     useChatStore.getState().clearMessages();
   },
+
+  // ========== 服务端持久化操作 ==========
+
+  /**
+   * 从服务端加载会话列表
+   */
+  loadSessionsFromServer: async (userId: string) => {
+    set({ loading: true });
+    try {
+      const sessions = await fetchSessions(userId);
+      set({ sessions, loading: false });
+    } catch {
+      set({ loading: false });
+    }
+  },
+
+  /**
+   * 从服务端加载指定会话的消息历史
+   */
+  loadMessagesFromServer: async (sessionId: string) => {
+    set({ loading: true });
+    try {
+      const resp = await fetchMessages(sessionId);
+      const rawMessages = resp.messages || [];
+      const msgs: Message[] = rawMessages.map((m: any, i: number) => ({
+        id: m.id ? String(m.id) : `hist_${i}_${Date.now()}`,
+        role: m.role,
+        content: m.content,
+        timestamp: typeof m.created_at === 'number' ? m.created_at : Date.now(),
+        isStreaming: false,
+      }));
+      set({ messages: msgs, loading: false });
+      useChatStore.getState().setMessages(msgs);
+    } catch {
+      set({ messages: [], loading: false });
+      useChatStore.getState().clearMessages();
+    }
+  },
+
+  /**
+   * 清空主对话的消息但保留会话本身
+   */
+  clearMainSessionMessages: async (sessionId: string) => {
+    const ok = await apiClearMessages(sessionId);
+    if (ok) {
+      set({ messages: [] });
+      useChatStore.getState().clearMessages();
+    }
+    return ok;
+  },
+
+  /**
+   * 删除会话并自动切换到下一个可用会话
+   */
+  deleteSessionAndRefresh: async (id: string, userId: string) => {
+    const ok = await apiDeleteSession(id);
+    if (!ok) return;
+
+    const state = get();
+    const remaining = state.sessions.filter((s) => s.id !== id);
+    const wasCurrent = state.currentSessionId === id;
+
+    // 更新本地列表
+    set({ sessions: remaining });
+
+    if (wasCurrent) {
+      if (remaining.length > 0) {
+        // 切换到列表中的第一个会话
+        const nextId = remaining[0].id;
+        set({ currentSessionId: nextId });
+        await get().loadMessagesFromServer(nextId);
+      } else {
+        // 没有会话了：管理员回到主对话，普通用户创建新对话
+        set({ currentSessionId: null, messages: [] });
+        useChatStore.getState().clearMessages();
+      }
+    }
+  },
+
+  /**
+   * 删除所有会话并重置状态
+   */
+  deleteAllSessionsAndReset: async (userId: string) => {
+    const ok = await apiDeleteAllSessions(userId);
+    if (!ok) return;
+
+    set({ sessions: [], currentSessionId: null, messages: [] });
+    useChatStore.getState().clearMessages();
+  },
+
+  /**
+   * 确保主对话存在（管理员用户）。若不存在则创建并返回。
+   */
+  ensureMainSession: async (userId: string) => {
+    const state = get();
+    // 先检查本地列表
+    const existing = state.sessions.find((s) => s.is_main);
+    if (existing) return existing;
+
+    // 本地没有，尝试从服务端加载
+    await get().loadSessionsFromServer(userId);
+    const refreshed = get().sessions.find((s) => s.is_main);
+    if (refreshed) return refreshed;
+
+    // 服务端也没有，创建主对话
+    const sid = randomID();
+    const created = await apiCreateSession(userId, sid, '主对话', true);
+    if (created) {
+      const newSession: Session = {
+        id: created.id,
+        user_id: created.user_id,
+        title: created.title,
+        is_main: created.is_main,
+        created_at: String(created.created_at),
+        updated_at: String(created.updated_at),
+        message_count: 0,
+      };
+      set((s) => ({ sessions: [newSession, ...s.sessions] }));
+      return newSession;
+    }
+    return null;
+  },
 }));