feat: topbar legacy-sync button, card view mode with cover fallback, year/month/day archives, richer page cache admin, stylevar repeater editor

- topbar: Livewire LegacySyncButton next to 写文章 (moved from user menu)
- view modes: add 图文(card) grid with cover fallback chain (cover → attachment → first content image → placeholder); list mode now title-only compact
- archives: year/month/day index grid
- page cache admin: size + expiry columns, total size, cache policy note
- theme inject: stylevars switch from KeyValue to Repeater with multi-line HTML editing
- import: html_entity_decode for category/post-title/link/keywords/comment author

resources/views/partials/view-mode-switcher.blade.php

@@ -6,4 +6,6 @@
     <a href="{{ \App\Blog\Support\HomeViewMode::url(\App\Blog\Support\HomeViewMode::FULL) }}" class="{{ $viewMode === \App\Blog\Support\HomeViewMode::FULL ? 'active' : '' }}">标准</a>
     <span>|</span>
     <a href="{{ \App\Blog\Support\HomeViewMode::url(\App\Blog\Support\HomeViewMode::LIST) }}" class="{{ $viewMode === \App\Blog\Support\HomeViewMode::LIST ? 'active' : '' }}">列表</a>
+    <span>|</span>
+    <a href="{{ \App\Blog\Support\HomeViewMode::url(\App\Blog\Support\HomeViewMode::CARD) }}" class="{{ $viewMode === \App\Blog\Support\HomeViewMode::CARD ? 'active' : '' }}">图文</a>
 </div>