chore: v5.7.0

- Remove APlayer/Meting music player support
- Upgrade Artalk to 2.10.0 and add vote feature
- Cache plugins.yml to avoid re-rendering on every generate
- Add null safety for error_404 and highlight config
- Fix series date timestamp format
- Enhance shuoshuo mockPost compatibility and error handling
- Prevent scrollbar flicker when fancybox is open
- Update plugin versions (docsearch, katex, twikoo)
- Bump version to 5.7.0

source/css/_global/index.styl

@@ -131,6 +131,10 @@ body
 *::-webkit-scrollbar-track
   background-color: transparent
 
+// make the scrollbar transparent when fancybox is open
+html.with-fancybox
+  --scrollbar-color: transparent
+
 input::placeholder
   color: var(--font-color)