feat(link): add external link guard feature support (#729)

* feat(external-link-guard): add native redirect mode and improve external-link guard UX

* fix(external-link-guard): remove redirect_url and clarify scope/new_tab_policy docs

* i18n(external-link-guard): localize guard texts across non-English locales

* feat(config)!: migrate `site.Params.externalIcon` to `site.Params.link.external_icon`

* refactor: implement regular and card link rendering

* feat(link-guard): implement link redirection page with copy and confirm functionality

* revert

* feat: implement link guard dialog for external links

---------

Co-authored-by: Cell <1024@lruihao.cn>

layouts/posts/single.html

@@ -33,7 +33,7 @@
             {{- $icon := dict "Class" "fa-solid fa-share" -}}
             {{- $iconTitle := cond (hasPrefix .Url "http") (printf "%v -> %v" (T "single.repost") .Url ) (T "single.repost") -}}
             {{- if hasPrefix .Url "http" -}}
-              {{ dict "Destination" .Url "Icon" $icon "Class" "icon-repost" "Title" $iconTitle | partial "plugin/link.html" -}}
+              {{ dict "Destination" .Url "Icon" $icon "Class" "icon-repost" "Title" $iconTitle "ExternalIcon" false | partial "plugin/link.html" -}}
             {{- else -}}
               <span title="{{ $iconTitle }}" class="icon-repost">{{- $icon | partial "plugin/icon.html" -}}</span>
             {{- end -}}
@@ -238,6 +238,7 @@
   </aside>
 
   {{- /* TOC Dialog */ -}}
+  {{- /* [todo] move to widgets.html */ -}}
   {{- if $showToc -}}
     <dialog id="toc-dialog" aria-labelledby="toc-dialog-title" role="dialog">
       <div class="toc">