fix: 修复公告关闭功能 - 当次关闭与永久关闭区分

问题：不管选择"当次关闭"还是"永久关闭"，都会永久关闭公告

修复：
- 当次关闭：使用 sessionStorage + pageToken
  - pageToken 基于 performance.timeOrigin 生成
  - 刷新页面后 token 变化，公告重新显示
- 永久关闭：使用 localStorage
  - 持久化存储，刷新/重开后不再显示

修改文件：
- app-frontend/src/layouts/AppLayout.vue
- templates/index.html

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/app/.vite/manifest.json

@@ -1,20 +1,20 @@
 {
-  "_accounts-sBYX3ZUA.js": {
-    "file": "assets/accounts-sBYX3ZUA.js",
+  "_accounts-BYq3lLev.js": {
+    "file": "assets/accounts-BYq3lLev.js",
     "name": "accounts",
     "imports": [
       "index.html"
     ]
   },
-  "_auth-GozuPnLT.js": {
-    "file": "assets/auth-GozuPnLT.js",
+  "_auth-xwgKTSGk.js": {
+    "file": "assets/auth-xwgKTSGk.js",
     "name": "auth",
     "imports": [
       "index.html"
     ]
   },
   "index.html": {
-    "file": "assets/index-Dzjm38x5.js",
+    "file": "assets/index-CGLq5RWF.js",
     "name": "index",
     "src": "index.html",
     "isEntry": true,
@@ -28,16 +28,16 @@
       "src/pages/ScreenshotsPage.vue"
     ],
     "css": [
-      "assets/index-Dfx-VTPl.css"
+      "assets/index-BIng7uZJ.css"
     ]
   },
   "src/pages/AccountsPage.vue": {
-    "file": "assets/AccountsPage-ZOKJprfz.js",
+    "file": "assets/AccountsPage-D387XNsv.js",
     "name": "AccountsPage",
     "src": "src/pages/AccountsPage.vue",
     "isDynamicEntry": true,
     "imports": [
-      "_accounts-sBYX3ZUA.js",
+      "_accounts-BYq3lLev.js",
       "index.html"
     ],
     "css": [
@@ -45,51 +45,51 @@
     ]
   },
   "src/pages/LoginPage.vue": {
-    "file": "assets/LoginPage-BrSs7jRF.js",
+    "file": "assets/LoginPage-D_X-BqcF.js",
     "name": "LoginPage",
     "src": "src/pages/LoginPage.vue",
     "isDynamicEntry": true,
     "imports": [
       "index.html",
-      "_auth-GozuPnLT.js"
+      "_auth-xwgKTSGk.js"
     ],
     "css": [
       "assets/LoginPage-CnwOLKJz.css"
     ]
   },
   "src/pages/RegisterPage.vue": {
-    "file": "assets/RegisterPage-TozgjjGu.js",
+    "file": "assets/RegisterPage-DxPLUv5i.js",
     "name": "RegisterPage",
     "src": "src/pages/RegisterPage.vue",
     "isDynamicEntry": true,
     "imports": [
       "index.html",
-      "_auth-GozuPnLT.js"
+      "_auth-xwgKTSGk.js"
     ],
     "css": [
       "assets/RegisterPage-BOcNcW5D.css"
     ]
   },
   "src/pages/ResetPasswordPage.vue": {
-    "file": "assets/ResetPasswordPage-CLFescRq.js",
+    "file": "assets/ResetPasswordPage-pZ9Ly5yR.js",
     "name": "ResetPasswordPage",
     "src": "src/pages/ResetPasswordPage.vue",
     "isDynamicEntry": true,
     "imports": [
       "index.html",
-      "_auth-GozuPnLT.js"
+      "_auth-xwgKTSGk.js"
     ],
     "css": [
       "assets/ResetPasswordPage-DybfLMAw.css"
     ]
   },
   "src/pages/SchedulesPage.vue": {
-    "file": "assets/SchedulesPage-CvQTwIDx.js",
+    "file": "assets/SchedulesPage-CWuZpJ5h.js",
     "name": "SchedulesPage",
     "src": "src/pages/SchedulesPage.vue",
     "isDynamicEntry": true,
     "imports": [
-      "_accounts-sBYX3ZUA.js",
+      "_accounts-BYq3lLev.js",
       "index.html"
     ],
     "css": [
@@ -97,7 +97,7 @@
     ]
   },
   "src/pages/ScreenshotsPage.vue": {
-    "file": "assets/ScreenshotsPage-BO_6agG8.js",
+    "file": "assets/ScreenshotsPage-DuTeRzLR.js",
     "name": "ScreenshotsPage",
     "src": "src/pages/ScreenshotsPage.vue",
     "isDynamicEntry": true,
@@ -109,7 +109,7 @@
     ]
   },
   "src/pages/VerifyResultPage.vue": {
-    "file": "assets/VerifyResultPage-DAOtFHKf.js",
+    "file": "assets/VerifyResultPage-CNbQc83z.js",
     "name": "VerifyResultPage",
     "src": "src/pages/VerifyResultPage.vue",
     "isDynamicEntry": true,