fix: 管理后台页面修复

- AdminLayout: 侧边栏布局和导航修复
- dal.ts: 数据访问层 API 调用修复
- Dashboard: 仪表盘统计卡片和数据加载修复
- Backtest: 回测配置和结果展示修复
- LLMConfig: LLM 配置页面修复
- Predictions: 预测管理页面修复

frontend/src/admin/AdminLayout.tsx

@@ -11,19 +11,31 @@ import { fetchAuthState, logout, UNAUTHORIZED_EVENT } from './api'
 import { fetchHealth } from './dal'
 import Login from './Login'
 
-const NAV_ITEMS = [
-  // ── 观测(只读) ──
-  { to: '/admin', label: '仪表盘', icon: '◇', end: true },
-  { to: '/admin/eval', label: '评估', icon: '◈' },
-  { to: '/admin/monitoring', label: '监控', icon: '◐' },
-  { to: '/admin/logs', label: '日志', icon: '▤' },
-  // ── 操作(写入,需登录) ──
-  { to: '/admin/predictions', label: '预测管理', icon: '◆' },
-  { to: '/admin/collection', label: '数据采集', icon: '◈' },
-  { to: '/admin/backtest', label: '回测', icon: '◉' },
-  { to: '/admin/data-sources', label: '数据源', icon: '◫' },
-  { to: '/admin/llm-config', label: 'LLM 配置', icon: '◬' },
-  { to: '/admin/config', label: '系统配置', icon: '◑' },
+const NAV_SECTIONS: { title: string; items: { to: string; label: string; icon: string; end?: boolean }[] }[] = [
+  {
+    title: '数据流水线',
+    items: [
+      { to: '/admin/collection', label: '数据采集', icon: '◈' },
+      { to: '/admin/predictions', label: '预测管理', icon: '◆' },
+      { to: '/admin/backtest', label: '回测', icon: '◉' },
+    ],
+  },
+  {
+    title: '评估与监控',
+    items: [
+      { to: '/admin/eval', label: '评估', icon: '◈' },
+      { to: '/admin/monitoring', label: '监控', icon: '◐' },
+      { to: '/admin/logs', label: '日志', icon: '▤' },
+    ],
+  },
+  {
+    title: '系统设置',
+    items: [
+      { to: '/admin/data-sources', label: '数据源', icon: '◫' },
+      { to: '/admin/llm-config', label: 'LLM 配置', icon: '◬' },
+      { to: '/admin/config', label: '系统配置', icon: '◑' },
+    ],
+  },
 ]
 
 /** 报眉日期行,与前台同款式 */
@@ -139,45 +151,65 @@ export default function AdminLayout() {
           <span className="text-2xs tracking-[0.25em] text-ink-400">ADMIN</span>
         </div>
 
-        {/* 导航:选中项以印报红方块标记,同前台胜平负选中样式 */}
-        <nav className="flex-1 overflow-y-auto px-3 py-4" aria-label="管理导航">
-          <ul className="space-y-0.5">
-            {NAV_ITEMS.map(item => (
-              <li key={item.to}>
-                <NavLink
-                  to={item.to}
-                  end={item.end}
-                  className={({ isActive }) =>
-                    `flex min-h-[44px] items-center gap-2.5 px-3 py-2.5 text-sm transition-colors ${
-                      isActive
-                        ? 'bg-press-wash/60 font-medium text-press'
-                        : 'text-ink-500 hover:bg-paper-100 hover:text-ink-900'
-                    }`
-                  }
-                >
-                  {({ isActive }) => (
-                    <>
+        {/* 导航:分组 + 小节标题 */}
+        <nav className="flex-1 overflow-y-auto px-3 py-3" aria-label="管理导航">
+          {/* 仪表盘独立(始终第一项) */}
+          <NavLink
+            to="/admin"
+            end
+            className={({ isActive }) =>
+              `flex min-h-[40px] items-center gap-2.5 px-3 text-sm transition-colors ${
+                isActive
+                  ? 'bg-press-wash/60 font-medium text-press'
+                  : 'text-ink-500 hover:bg-paper-100 hover:text-ink-900'
+              }`
+            }
+          >
+            <span className="text-base leading-none opacity-50" aria-hidden="true">◇</span>
+            仪表盘
+          </NavLink>
+
+          {NAV_SECTIONS.map(section => (
+            <div key={section.title} className="mt-4">
+              <p className="mb-1 px-3 text-2xs font-medium uppercase tracking-widest text-ink-400">
+                {section.title}
+              </p>
+              <ul className="space-y-0.5">
+                {section.items.map(item => (
+                  <li key={item.to}>
+                    <NavLink
+                      to={item.to}
+                      className={({ isActive }) =>
+                        `flex min-h-[40px] items-center gap-2.5 px-3 text-sm transition-colors ${
+                          isActive
+                            ? 'bg-press-wash/60 font-medium text-press'
+                            : 'text-ink-500 hover:bg-paper-100 hover:text-ink-900'
+                        }`
+                      }
+                    >
                       <span
-                        className={`inline-block h-1.5 w-1.5 flex-shrink-0 ${isActive ? 'bg-press' : 'bg-transparent'}`}
+                        className={`inline-block h-1.5 w-1.5 flex-shrink-0 ${
+                          location.pathname.startsWith(item.to) ? 'bg-press' : 'bg-transparent'
+                        }`}
                         aria-hidden="true"
                       />
                       <span className="text-base leading-none opacity-50" aria-hidden="true">
                         {item.icon}
                       </span>
                       {item.label}
-                    </>
-                  )}
-                </NavLink>
-              </li>
-            ))}
-          </ul>
+                    </NavLink>
+                  </li>
+                ))}
+              </ul>
+            </div>
+          ))}
         </nav>
 
         {/* 底部 */}
         <div className="border-t border-ink-200 px-4 py-3">
           <a
             href="/"
-            className="flex min-h-[44px] items-center gap-2 text-xs text-ink-500 transition-colors hover:text-press"
+            className="flex min-h-[36px] items-center gap-2 text-xs text-ink-500 transition-colors hover:text-press"
           >
             <span aria-hidden="true">←</span>
             返回前台版面
@@ -212,13 +244,6 @@ export default function AdminLayout() {
               />
               {healthOk === null ? '检测中' : healthOk ? '系统正常' : '系统异常'}
             </span>
-            <a
-              href="/"
-              className="text-press transition-colors hover:text-press-dark sm:hidden"
-              aria-label="返回前台"
-            >
-              前台
-            </a>
             <button
               onClick={handleLogout}
               className="text-ink-500 transition-colors hover:text-press"