feat(admin): 登录改页内弹窗 + P1 站点设置（页头/侧栏）

- 登录：LoginDialog（Modal）替代 /login 页面；/login 重定向回首页
- 设置接口：GET /api/settings 公开读、PATCH 需登录 + version 乐观锁（409/400）
- setting 表存 site JSON：页头（启用/速度/条目+标签+色调）、侧栏（hidden/order）
- /admin：Tabs 页头/侧栏，条目增删与上下移，保存后首页生效
- 首页应用设置：ticker 文本占位符与速度、侧栏顺序与显隐
- 测试 42 passed（settings 5 例）

stash-web/src/App.tsx

@@ -29,6 +29,13 @@ import { useProjects } from './useProjects'
 import { useCatalog } from './useCatalog'
 import { useViewRoute } from './useViewRoute'
 import { fetchSession, logout as logoutRequest, type SessionState } from './auth'
+import {
+  applySidebarSettings,
+  defaultSettings,
+  fetchSettings,
+  type SettingsDocument,
+} from './settings'
+import { LoginDialog } from './components/auth/LoginDialog'
 import { parseViewPath, viewPath, type View } from './data/view'
 import './App.css'
 
@@ -40,6 +47,11 @@ export default function App() {
   // 当前视图由地址栏决定：刷新 / 收藏 / 前进后退都回到同一页（见 useViewRoute.ts）
   const { view, go } = useViewRoute()
   const [session, setSession] = useState<SessionState | null>(null)
+  const [settings, setSettings] = useState<SettingsDocument>({
+    version: 0,
+    settings: defaultSettings(),
+  })
+  const [loginOpen, setLoginOpen] = useState(false)
   const [scrolled, setScrolled] = useState(false)
   const searchRef = useRef<HTMLInputElement>(null)
 
@@ -49,6 +61,9 @@ export default function App() {
     fetchSession().then((next) => {
       if (alive) setSession(next)
     })
+    fetchSettings().then((next) => {
+      if (alive) setSettings(next)
+    })
     return () => {
       alive = false
     }
@@ -63,13 +78,17 @@ export default function App() {
     [categories, keyword],
   )
 
-  // 侧栏不显示「本地服务」，也不显示被标记 show_in_sidebar = 0 的分区
+  // 侧栏不显示「本地服务」，也不显示被标记 show_in_sidebar = 0 的分区；
+  // 再按 /admin 里的顺序与显隐设置重排一遍
   const sidebarCategories = useMemo(
     () =>
-      categories.filter(
-        (category) => category.id !== 'local' && category.showInSidebar !== false,
+      applySidebarSettings(
+        categories.filter(
+          (category) => category.id !== 'local' && category.showInSidebar !== false,
+        ),
+        settings.settings.sidebar,
       ),
-    [categories],
+    [categories, settings.settings.sidebar],
   )
 
   const detailView = view.type === 'detail' ? view : undefined
@@ -258,11 +277,24 @@ export default function App() {
   }
 
   const handleLogout = () => {
-    void logoutRequest().then(() => window.location.assign('/'))
+    void logoutRequest().then(() => {
+      setSession({ authenticated: false, has_admin: true })
+    })
   }
 
   return (
     <>
+      {/* 登录弹窗：成功后直接把会话状态写回，不刷新页面 */}
+      <LoginDialog
+        open={loginOpen}
+        hasAdmin={session?.has_admin ?? false}
+        onClose={() => setLoginOpen(false)}
+        onSuccess={(next) => {
+          setSession(next)
+          setLoginOpen(false)
+        }}
+      />
+
       {/* 主题的顶部背景图：固定 65vh，底部渐隐到页面底色 */}
       <div className="site-background" aria-hidden="true" />
 
@@ -287,11 +319,15 @@ export default function App() {
             projectCount={projects.length}
             sampleProject={projects[0]?.name}
             live={live}
+            headerItems={settings.settings.header.items}
+            headerEnabled={settings.settings.header.enabled}
+            headerSpeed={settings.settings.header.speed}
             authenticated={session?.authenticated === true}
             username={session?.username ?? undefined}
             onFocusSearch={() => searchRef.current?.focus()}
-            onLogin={() => window.location.assign('/login')}
+            onLogin={() => setLoginOpen(true)}
             onLogout={handleLogout}
+            onSettings={() => window.location.assign('/admin')}
           />
         }
         sider={