fix(mini-program): 修复 logo.svg 500 错误

问题:
- 小程序请求 /static/logo.svg 返回 500 错误
- logo.svg 文件在 src/static/ 目录，但编译后未被复制到输出目录

修复:
1. 在 mini-program/ 根目录创建 static/ 目录
2. 将 logo.svg 复制到 mini-program/static/logo.svg
3. 修改 vite.config.js 添加 publicDir 配置，让 Vite 复制 static 目录
4. 更新图片路径：/static/logo.svg → /logo.svg
   - pages/splash/index.vue
   - pages/main/index.vue

效果:
- logo.svg 正确编译到 unpackage/dist/dev/mp-weixin/logo.svg
- 小程序正常加载 logo 图片
- 不再出现 500 错误

mini-program/static/logo.svg

@@ -0,0 +1,67 @@
+<svg width="1024" height="1024" viewBox="0 0 1024 1024" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <!-- 主渐变：使用项目主题色 -->
+    <linearGradient id="bgGradient" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#A855F7;stop-opacity:1" />
+      <stop offset="50%" style="stop-color:#9333EA;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#7C3AED;stop-opacity:1" />
+    </linearGradient>
+
+    <!-- 柱廊渐变 -->
+    <linearGradient id="pillarGradient" x1="0%" y1="0%" x2="0%" y2="100%">
+      <stop offset="0%" style="stop-color:#C084FC;stop-opacity:0.9" />
+      <stop offset="100%" style="stop-color:#A855F7;stop-opacity:0.7" />
+    </linearGradient>
+
+    <!-- 核心发光渐变 -->
+    <radialGradient id="coreGlow" cx="50%" cy="50%" r="50%">
+      <stop offset="0%" style="stop-color:#E879F9;stop-opacity:1" />
+      <stop offset="50%" style="stop-color:#A855F7;stop-opacity:0.8" />
+      <stop offset="100%" style="stop-color:#A855F7;stop-opacity:0" />
+    </radialGradient>
+
+    <!-- 发光滤镜 -->
+    <filter id="glow" x="-50%" y="-50%" width="200%" height="200%">
+      <feGaussianBlur stdDeviation="15" result="coloredBlur"/>
+      <feMerge>
+        <feMergeNode in="coloredBlur"/>
+        <feMergeNode in="SourceGraphic"/>
+      </feMerge>
+    </filter>
+  </defs>
+
+  <!-- 背景圆角正方形 -->
+  <rect x="40" y="40" width="944" height="944" rx="200" fill="url(#bgGradient)"/>
+
+  <!-- 背景光晕 -->
+  <circle cx="512" cy="512" r="300" fill="url(#coreGlow)" opacity="0.5"/>
+
+  <!-- 神殿柱廊：三根柱子 -->
+  <!-- 左柱 -->
+  <rect x="280" y="320" width="60" height="384" rx="30" fill="url(#pillarGradient)" filter="url(#glow)"/>
+  <!-- 中柱 -->
+  <rect x="482" y="280" width="60" height="464" rx="30" fill="url(#pillarGradient)" filter="url(#glow)"/>
+  <!-- 右柱 -->
+  <rect x="684" y="320" width="60" height="384" rx="30" fill="url(#pillarGradient)" filter="url(#glow)"/>
+
+  <!-- 柱顶横梁 -->
+  <path d="M240 300 L784 300 L784 340 L240 340 Z" fill="url(#pillarGradient)" opacity="0.8"/>
+
+  <!-- 中心情绪核心：发光的椭圆 -->
+  <ellipse cx="512" cy="540" rx="80" ry="100" fill="white" filter="url(#glow)" opacity="0.95"/>
+  <ellipse cx="512" cy="540" rx="50" ry="70" fill="url(#coreGlow)" filter="url(#glow)"/>
+
+  <!-- 顶部星芒：呼应星海概念 -->
+  <path d="M512 180 L524 220 L564 220 L532 244 L544 284 L512 260 L480 284 L492 244 L460 220 L500 220 Z"
+        fill="#E879F9" filter="url(#glow)"/>
+
+  <!-- 底部装饰弧线 -->
+  <path d="M320 780 Q512 840 704 780" stroke="#C084FC" stroke-width="6" stroke-linecap="round" fill="none" opacity="0.6"/>
+  <path d="M360 820 Q512 860 664 820" stroke="#C084FC" stroke-width="4" stroke-linecap="round" fill="none" opacity="0.4"/>
+
+  <!-- 四角装饰：星光点缀 -->
+  <circle cx="160" cy="160" r="8" fill="#C084FC" filter="url(#glow)" opacity="0.8"/>
+  <circle cx="864" cy="160" r="8" fill="#C084FC" filter="url(#glow)" opacity="0.8"/>
+  <circle cx="160" cy="864" r="8" fill="#C084FC" filter="url(#glow)" opacity="0.8"/>
+  <circle cx="864" cy="864" r="8" fill="#C084FC" filter="url(#glow)" opacity="0.8"/>
+</svg>