fix: resolve all ESLint errors in Vue components

Fixed 22 ESLint errors across 26 Vue component files:
- Removed TypeScript type annotations from ReadingProgress.vue (converted to JS)
- Removed unused variables, imports, and duplicate function declarations
- Fixed HTML parsing errors (invalid attribute names, unclosed tags)
- Added missing :key directives to v-for loops
- Fixed duplicate object keys (backgroundImage)
- Replaced special characters in comments to avoid parsing issues
- Fixed malformed HTML tags (v-else", 003e attributes)

All warnings were left unchanged as requested. Build now passes with 0 errors.

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

docs/.vitepress/theme/components/appendix/cache-design/CacheMonitoringDashboardDemo.vue

@@ -153,7 +153,7 @@
 
     <div class="info-box">
       <span class="icon">💡</span>
-      <strong>核心指标：</strong>命中率应该 > 80%，响应时间 < 10ms，内存使用 < 80%。如果命中率突然下降，可能是缓存穿透或雪崩；如果响应时间变长，可能是缓存满了。
+      <strong>核心指标：</strong>命中率应该 &gt; 80%，响应时间 &lt; 10ms，内存使用 &lt; 80%。如果命中率突然下降，可能是缓存穿透或雪崩；如果响应时间变长，可能是缓存满了。
     </div>
   </div>
 </template>