improvement(wrapped): 年度总结仅保留 Modern 主题

- 移除复古主题切换入口（控制面板/左上角按钮）与 Win98/CRT 相关 UI

- 简化 useWrappedTheme：仅保留 off(Modern)，历史主题值自动回退

- Modern 下也展示 LuckyBlock 占位图，并同步更新 README 说明

frontend/composables/useWrappedTheme.js

@@ -1,109 +1,31 @@
 /**
  * 年度总结页面主题管理 composable
- * 支持三种主题：modern（现代）、gameboy（Game Boy）、win98（Windows 98）
+ * 仅保留 modern（现代）主题
  */
 
-const STORAGE_KEY = 'wrapped-theme'
-const VALID_THEMES = ['off', 'gameboy', 'win98']
-const RETRO_THEMES = new Set(['gameboy'])
-
 // 全局响应式状态（跨组件共享）
-const theme = ref('off')
-let initialized = false
-let keyboardInitialized = false
+// Note: 历史上曾尝试过 gameboy / win98 等主题，但目前已移除，仅保留 Modern。
+const theme = ref('off') // off === Modern
 
 export function useWrappedTheme() {
-  // 初始化：从 localStorage 读取（仅执行一次）
-  const initTheme = () => {
-    if (initialized || !import.meta.client) return
-    const saved = localStorage.getItem(STORAGE_KEY)
-    if (saved && VALID_THEMES.includes(saved)) {
-      theme.value = saved
-    }
-    initialized = true
-  }
-
-  // 设置主题
   const setTheme = (newTheme) => {
-    if (!VALID_THEMES.includes(newTheme)) {
-      console.warn(`Invalid theme: ${newTheme}`)
-      return
-    }
-    theme.value = newTheme
-    if (import.meta.client) {
-      localStorage.setItem(STORAGE_KEY, newTheme)
+    // Only keep Modern.
+    if (newTheme !== 'off') {
+      console.warn(`Wrapped theme '${newTheme}' has been removed; falling back to Modern.`)
     }
+    theme.value = 'off'
   }
 
-  // 切换到下一个主题（循环）
-  const cycleTheme = () => {
-    const currentIndex = VALID_THEMES.indexOf(theme.value)
-    const nextIndex = (currentIndex + 1) % VALID_THEMES.length
-    setTheme(VALID_THEMES[nextIndex])
-  }
+  const cycleTheme = () => setTheme('off')
 
-  // 计算属性：是否为复古模式（非 off）
-  const isRetro = computed(() => theme.value !== 'off')
-
-  // 计算属性：当前主题的 CSS 类名
-  const themeClass = computed(() => {
-    if (theme.value === 'off') return ''
-    // Note: not every non-modern theme is "retro pixel/CRT".
-    // Keep wrapped-retro for themes that rely on pixel/CRT shared styles.
-    const base = RETRO_THEMES.has(theme.value) ? 'wrapped-retro ' : ''
-    return `${base}wrapped-theme-${theme.value}`
-  })
-
-  // 计算属性：主题显示名称
-  const themeName = computed(() => {
-    const names = {
-      off: 'Modern',
-      gameboy: 'Game Boy',
-      win98: 'Windows 98'
-    }
-    return names[theme.value] || 'Modern'
-  })
-
-  // 全局 F1-F3 快捷键切换主题（仅初始化一次）
-  const initKeyboardShortcuts = () => {
-    if (keyboardInitialized || !import.meta.client) return
-    keyboardInitialized = true
-
-    const handleKeydown = (e) => {
-      // 检查是否在可编辑元素中
-      const el = e.target
-      if (el && (el.tagName === 'INPUT' || el.tagName === 'TEXTAREA' || el.tagName === 'SELECT' || el.isContentEditable)) {
-        return
-      }
-
-      if (e.key === 'F1') {
-        e.preventDefault()
-        setTheme('off')
-      } else if (e.key === 'F2') {
-        e.preventDefault()
-        setTheme('gameboy')
-      } else if (e.key === 'F3') {
-        e.preventDefault()
-        setTheme('win98')
-      }
-    }
-
-    window.addEventListener('keydown', handleKeydown)
-  }
-
-  // 客户端挂载后再初始化：避免 SSR 与首帧 hydration 不一致
-  onMounted(() => {
-    initTheme()
-    initKeyboardShortcuts()
-  })
+  const isRetro = computed(() => false)
+  const themeClass = computed(() => '')
 
   return {
     theme: readonly(theme),
     setTheme,
     cycleTheme,
     isRetro,
-    themeClass,
-    themeName,
-    VALID_THEMES
+    themeClass
   }
 }