a11y: fix all remaining WCAG 2.1 AA issues from audit round 2

- Focus traps for fediverse modal and lightbox dialogs (C3, C4)
- Search widget input label (C5)
- Blogroll widget tab ARIA semantics (C6)
- Footer social links "opens in new tab" warning (S5)
- Reply context aria-label on aside (S8)
- Photo alt text fallback includes post title (S10)
- Post categories use list markup (M3)
- Funkwhale now-playing bars aria-hidden (M7)
- TOC uses static Tailwind classes instead of dynamic (M9)
- Footer headings use proper aria heading roles (M15)
- Header anchor opacity increased to 1 for contrast (M18)
- Custom HTML widgets labeled as regions (M19)
- Empty collection placeholder role=status (M22)
- GitHub widget loading state announced (N5)
- Subscribe icon contrast improved (m1)
- All Permalink links have aria-label with post context (m3)
- Podroll audio element aria-label (m4)
- Obfuscated email link aria-label (m6)
- Fediverse follow button uses aria-label (M10)

Score: 53.6% → 92.9% (26/28 WCAG criteria passing)

Confab-Link: http://localhost:8080/sessions/0ec83454-d346-4329-8aaf-6b12139bf596

blog.njk

@@ -90,7 +90,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
             {{ post.templateContent | safe }}
           </div>
           {% endif %}
-          <a class="u-url text-sm text-red-600 dark:text-red-400 hover:underline mt-3 inline-block" href="{{ post.url }}">Permalink</a>
+          <a class="u-url text-sm text-red-600 dark:text-red-400 hover:underline mt-3 inline-block" href="{{ post.url }}" aria-label="Permalink: {{ post.data.title or ('Like from ' + (post.date | dateDisplay)) }}">Permalink</a>
         </div>
       </div>
 
@@ -134,7 +134,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
             {{ post.templateContent | safe }}
           </div>
           {% endif %}
-          <a class="u-url text-sm text-amber-600 dark:text-amber-400 hover:underline mt-3 inline-block" href="{{ post.url }}">Permalink</a>
+          <a class="u-url text-sm text-amber-600 dark:text-amber-400 hover:underline mt-3 inline-block" href="{{ post.url }}" aria-label="Permalink: {{ post.data.title or ('Bookmark from ' + (post.date | dateDisplay)) }}">Permalink</a>
         </div>
       </div>
 
@@ -173,7 +173,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
             {{ post.templateContent | safe }}
           </div>
           {% endif %}
-          <a class="u-url text-sm text-green-600 dark:text-green-400 hover:underline mt-3 inline-block" href="{{ post.url }}">Permalink</a>
+          <a class="u-url text-sm text-green-600 dark:text-green-400 hover:underline mt-3 inline-block" href="{{ post.url }}" aria-label="Permalink: {{ post.data.title or ('Repost from ' + (post.date | dateDisplay)) }}">Permalink</a>
         </div>
       </div>
 
@@ -210,7 +210,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
           <div class="e-content prose dark:prose-invert prose-sm mt-3 max-w-none">
             {{ post.templateContent | safe }}
           </div>
-          <a class="u-url text-sm text-sky-600 dark:text-sky-400 hover:underline mt-3 inline-block" href="{{ post.url }}">Permalink</a>
+          <a class="u-url text-sm text-sky-600 dark:text-sky-400 hover:underline mt-3 inline-block" href="{{ post.url }}" aria-label="Permalink: {{ post.data.title or ('Reply from ' + (post.date | dateDisplay)) }}">Permalink</a>
         </div>
       </div>
 
@@ -257,7 +257,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
             {{ post.templateContent | safe }}
           </div>
           {% endif %}
-          <a class="u-url text-sm text-purple-600 dark:text-purple-400 hover:underline mt-3 inline-block" href="{{ post.url }}">Permalink</a>
+          <a class="u-url text-sm text-purple-600 dark:text-purple-400 hover:underline mt-3 inline-block" href="{{ post.url }}" aria-label="Permalink: {{ post.data.title or ('Photo from ' + (post.date | dateDisplay)) }}">Permalink</a>
         </div>
       </div>
 
@@ -317,7 +317,7 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
         {{ post.templateContent | safe }}
       </div>
       <div class="post-footer mt-3">
-        <a href="{{ post.url }}" class="text-sm text-teal-600 dark:text-teal-400 hover:underline">
+        <a href="{{ post.url }}" class="text-sm text-teal-600 dark:text-teal-400 hover:underline" aria-label="Permalink: {{ post.data.title or ('Note from ' + (post.date | dateDisplay)) }}">
           Permalink
         </a>
       </div>