improvement(wrapped-ui): 下线 DOS 主题并优化 Wrapped 多主题体验

- 移除 DOS 主题入口、切换器组件与相关样式逻辑，统一主题为 Modern / GameBoy / Win98。

- 新增 WrappedGameboyDither 组件，并在背景与 CRT 叠加层中引入 GameBoy 噪点效果。

- 优化 wrapped 页面视口高度与背景同步逻辑（含 ResizeObserver 与 100dvh 适配），提升桌面容器显示稳定性。

- 调整封面标题与预览位移、回复速度卡片滚动行为等细节，提升主题下视觉与交互一致性。

frontend/components/wrapped/shared/WrappedGameboyDither.vue

@@ -0,0 +1,98 @@
+<template>
+  <canvas
+    ref="grainRef"
+    class="pointer-events-none absolute inset-0 h-full w-full"
+    :style="canvasStyle"
+    aria-hidden="true"
+  ></canvas>
+</template>
+
+<script setup>
+import { computed, onBeforeUnmount, onMounted, ref } from 'vue'
+
+const props = defineProps({
+  patternRefreshInterval: {
+    type: Number,
+    default: 2
+  },
+  patternAlpha: {
+    type: Number,
+    default: 20
+  },
+  mixBlendMode: {
+    type: String,
+    default: 'multiply'
+  },
+  patternSize: {
+    type: Number,
+    default: 512
+  }
+})
+
+const grainRef = ref(null)
+
+const canvasStyle = computed(() => `image-rendering: pixelated; mix-blend-mode: ${props.mixBlendMode};`)
+
+let animationId = 0
+let frame = 0
+let noiseData
+let noise32
+
+const clamp = (value, min, max) => Math.min(max, Math.max(min, value))
+
+const resize = () => {
+  const canvas = grainRef.value
+  if (!canvas) return
+  const size = Math.max(64, Math.round(props.patternSize))
+  canvas.width = size
+  canvas.height = size
+}
+
+const initImageData = (ctx) => {
+  const canvas = grainRef.value
+  if (!canvas) return
+  noiseData = ctx.createImageData(canvas.width, canvas.height)
+  noise32 = new Uint32Array(noiseData.data.buffer)
+}
+
+const drawGrain = () => {
+  if (!noise32) return
+  const alpha = clamp(Math.round(props.patternAlpha), 0, 255) << 24
+  for (let i = 0; i < noise32.length; i++) {
+    const value = (Math.random() * 255) | 0
+    noise32[i] = alpha | (value << 16) | (value << 8) | value
+  }
+}
+
+const loop = (ctx) => {
+  const refreshEvery = Math.max(1, Math.round(props.patternRefreshInterval))
+  if (frame % refreshEvery === 0) {
+    drawGrain()
+    ctx.putImageData(noiseData, 0, 0)
+  }
+
+  frame++
+  animationId = window.requestAnimationFrame(() => loop(ctx))
+}
+
+onMounted(() => {
+  const canvas = grainRef.value
+  if (!canvas) return
+
+  const ctx = canvas.getContext('2d', { alpha: true })
+  if (!ctx) return
+
+  resize()
+  initImageData(ctx)
+  drawGrain()
+  ctx.putImageData(noiseData, 0, 0)
+  loop(ctx)
+
+  window.addEventListener('resize', resize)
+})
+
+onBeforeUnmount(() => {
+  window.removeEventListener('resize', resize)
+  window.cancelAnimationFrame(animationId)
+})
+</script>