feat(admin): art-design-pro integration with local session auth

P1b Task 9: apps/admin based on art-design-pro v3.0.2 (tag, commit
d224dd4; source recorded in apps/admin/SOURCE.md), trimmed to
layout/login/i18n/request/table-form core. Login wired to real
POST /v1/auth/password (single-token session), Bearer header on all
requests, 401 interceptor logout+redirect, request-driven sliding
renewal (refresh at ~80% TTL, single-flight), best-effort
POST /v1/auth/logout on user-menu logout. One protected stub page
(相册管理). Dev port 5176 strictPort + /v1 proxy to 8080. Admin keeps
its own eslint9 flat config; root eslint ignores apps/admin/**.
vitest unit tests for renewal pacing + Playwright e2e (guard redirect,
localized wrong-password error, login lands on stub, token persists
across reload, logout clears session).

Co-Authored-By: Claude Code <noreply@anthropic.com>

apps/admin/index.html

@@ -0,0 +1,47 @@
+<!doctype html>
+<html>
+  <head>
+    <title>Photo Live Admin</title>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta
+      name="description"
+      content="Art Design Pro - A modern admin dashboard template built with Vue 3, TypeScript, and Element Plus."
+    />
+    <link rel="shortcut icon" type="image/x-icon" href="src/assets/images/favicon.ico" />
+
+    <style>
+      /* 防止页面刷新时白屏的初始样式 */
+      html {
+        background-color: #fafbfc;
+      }
+
+      html.dark {
+        background-color: #070707;
+      }
+    </style>
+
+    <script>
+      // 初始化 html class 主题属性
+      ;(function () {
+        try {
+          if (typeof Storage === 'undefined' || !window.localStorage) {
+            return
+          }
+
+          const themeType = localStorage.getItem('sys-theme')
+          if (themeType === 'dark') {
+            document.documentElement.classList.add('dark')
+          }
+        } catch (e) {
+          console.warn('Failed to apply initial theme:', e)
+        }
+      })()
+    </script>
+  </head>
+
+  <body>
+    <div id="app"></div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>