Mobile: center pinned post, pagination fixes, minor layout tweaks

- First (pinned) post on mobile: title and image centered
- Pagination: restored page counter on mobile, buttons above footer
- Typography and layout minor improvements

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

themes/hugo-theme-massively/layouts/partials/posts/list.html

@@ -10,7 +10,7 @@
             <h2><a href="{{ .Permalink }}">{{ .Title }}</a></h2>
         </header>
         {{ if .Params.image }}
-        <a href="{{ .Permalink }}" class="image main"><img src="{{ .Params.image | relURL }}" alt="" /></a>
+        <a href="{{ .Permalink }}" class="image main"><img src="{{ .Params.image | relURL }}" alt="{{ .Title }}" loading="lazy" /></a>
         {{ end }}
         {{ if .Description }}
         <p>{{ .Description }}</p>