feat(wrapped-ui): 新增 Win98 主题与桌面化外观

- 主题系统新增 win98（显示名 Windows 98，快捷键扩展到 F1-F4），并区分 retro(pixel/CRT) 与桌面 GUI 主题
- 年度总结页新增 Win98 桌面背景与底部任务栏（背景色/视口高度适配）
- 封面与卡片 slide 形态支持 Win98 窗口外观（title bar/icon/controls）
- 主题切换器补充 Win98 选项并新增 Win98 专属切换器
- 新增 Win98 图标资源（Start + 桌面图标）

frontend/pages/wrapped/index.vue

@@ -7,7 +7,8 @@
   >
     <!-- PPT 风格：单张卡片占据全页面，鼠标滚轮切换 -->
     <WrappedDeckBackground />
-    <WrappedCRTOverlay v-if="isRetro" />
+    <!-- CRT 叠加层仅用于“像素屏/终端”类主题，Win98 等桌面 GUI 主题不应开启 -->
+    <WrappedCRTOverlay v-if="theme === 'gameboy' || theme === 'dos'" />
 
     <!-- 左上角：刷新 + 复古模式开关 -->
     <div class="absolute top-6 left-6 z-20 select-none">
@@ -164,6 +165,12 @@
         </WrappedCardShell>
       </section>
     </div>
+
+    <!-- Win98：底部任务栏 -->
+    <WrappedWin98Taskbar
+      v-if="theme === 'win98'"
+      :title="taskbarTitle"
+    />
   </div>
 </template>
 
@@ -219,7 +226,8 @@ let navUnlockTimer = null
 const THEME_BG = {
   off: '#F3FFF8',       // Modern: 浅绿
   gameboy: '#9bbc0f',   // Game Boy: 亮绿
-  dos: '#0a0a0a'        // DOS: 黑色
+  dos: '#0a0a0a',       // DOS: 黑色
+  win98: '#008080'      // Win98: 经典桌面青色
 }
 
 const slides = computed(() => {
@@ -229,6 +237,14 @@ const slides = computed(() => {
   return out
 })
 
+const taskbarTitle = computed(() => {
+  if (theme.value !== 'win98') return ''
+  if (activeIndex.value === 0) return `${year.value} WeChat Wrapped`
+  const idx = activeIndex.value - 1
+  const c = report.value?.cards?.[idx]
+  return String(c?.title || 'WeChat Wrapped')
+})
+
 const currentBg = computed(() => THEME_BG[theme.value] || THEME_BG.off)
 
 const slideStyle = computed(() => (
@@ -356,8 +372,11 @@ const onTouchEnd = (e) => {
 const updateViewport = () => {
   const h = deckEl.value?.clientHeight || window.innerHeight || 0
   if (!h) return
+  // Reserve space for the Win98 taskbar at the bottom.
+  const offset = theme.value === 'win98' ? 40 : 0
+  const effective = Math.max(0, h - offset)
   // Avoid endless reflows from 1px rounding errors (especially in Electron).
-  if (Math.abs(viewportHeight.value - h) > 1) viewportHeight.value = h
+  if (Math.abs(viewportHeight.value - effective) > 1) viewportHeight.value = effective
 }
 
 const loadAccounts = async () => {
@@ -515,6 +534,11 @@ onMounted(async () => {
   }
 })
 
+// Theme switch may change reserved UI space (e.g., Win98 taskbar)
+watch(theme, () => {
+  updateViewport()
+})
+
 onBeforeUnmount(() => {
   window.removeEventListener('resize', updateViewport)
   deckEl.value?.removeEventListener('wheel', onWheel)