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

devtools/public/index.html

@@ -744,19 +744,22 @@ async function renderDashboard() {
       <div class="cards-grid cards-4" id="dashboard-svc-cards"></div>
     </div>
 
-    <!-- 数据库连接状态 -->
-    <div class="card">
+    <!-- 数据库状态卡片 -->
+    <div class="card" id="db-card">
       <div class="card-header">
-        <span class="card-title">🗄️ 数据库连接</span>
-        ${data.database?.checked ? `
-          <span class="badge ${data.database.postgresAlive ? 'badge-running' : 'badge-error'}">
-            PostgreSQL ${data.database.postgresAlive ? '通联' : '断开'}
-          </span>
-          <span class="badge ${data.database.tunnelRunning ? 'badge-running' : 'badge-stopped'}" style="margin-left:6px">
-            隧道 ${data.database.tunnelRunning ? '运行中' : '未运行'}
-          </span>
-        ` : '<span class="badge badge-stopped">待检查</span>'}
-        <a href="#" onclick="switchPanel('database');return false" style="font-size:11px;color:var(--accent);text-decoration:none">🔍 详情 →</a>
+        <span class="card-title">🗄️ 数据库</span>
+        <span class="badge badge-stopped" id="db-status-badge">检查中...</span>
+      </div>
+      <div class="metrics">
+        <div class="metric"><div class="value" id="db-type-display">PostgreSQL</div><div class="label">类型</div></div>
+        <div class="metric"><div class="value" id="db-port-display">5432</div><div class="label">端口</div></div>
+        <div class="metric"><div class="value" id="db-uptime-display">—</div><div class="label">状态</div></div>
+      </div>
+      <div class="btn-group" style="margin-top:10px">
+        <button class="btn btn-xs btn-green" onclick="controlDB('start')">▶ 启动</button>
+        <button class="btn btn-xs btn-red" onclick="controlDB('stop')">⏹ 停止</button>
+        <button class="btn btn-xs" onclick="controlDB('restart')">🔄 重启</button>
+        <a href="#" onclick="switchPanel('database');return false" style="font-size:10px;color:var(--accent);text-decoration:none;margin-left:auto;align-self:center">🔍 详情 →</a>
       </div>
     </div>
 
@@ -789,6 +792,9 @@ async function renderDashboard() {
   // 渲染服务卡片
   renderDashboardSvcCards(svcs);
 
+  // 渲染数据库卡片
+  renderDBCard();
+
   // 渲染性能快照
   const perfContainer = document.getElementById('dashboard-perf');
   const perf = data.performance?.perService || {};
@@ -1701,6 +1707,42 @@ async function tunnelAction(action) {
   }
 }
 
+// ========== 数据库卡片控制 ==========
+async function renderDBCard() {
+  const data = await api('/api/db/status');
+  const badge = document.getElementById('db-status-badge');
+  const typeDisplay = document.getElementById('db-type-display');
+  const portDisplay = document.getElementById('db-port-display');
+  const uptimeDisplay = document.getElementById('db-uptime-display');
+
+  if (data.error) {
+    if (badge) { badge.textContent = '错误'; badge.className = 'badge badge-error'; }
+    if (uptimeDisplay) uptimeDisplay.textContent = '错误';
+    return;
+  }
+
+  const online = data.online;
+  if (badge) {
+    badge.textContent = online ? '🟢 在线' : '🔴 离线';
+    badge.className = 'badge ' + (online ? 'badge-running' : 'badge-error');
+  }
+  if (typeDisplay) typeDisplay.textContent = 'PostgreSQL';
+  if (portDisplay) portDisplay.textContent = data.port || 5432;
+  if (uptimeDisplay) uptimeDisplay.textContent = online ? '已连接' : '未连接';
+}
+
+async function controlDB(action) {
+  showToast('正在' + action + '数据库...', 'info');
+  const data = await api('/api/db/' + action, { method: 'POST' });
+  if (data.error) {
+    showToast('操作失败: ' + data.error, 'error');
+  } else {
+    showToast('数据库 ' + action + ' 完成', 'success');
+    // 等待2秒后刷新状态
+    setTimeout(renderDBCard, 2000);
+  }
+}
+
 </script>
 <script src="iot-panel.js"></script>
 <script>