fix: reduce amber saturation in Featured section dark mode

Article title links now have explicit text color instead of inheriting
the global amber link color. Default article left-border changed from
amber to neutral surface tone. Card hover border toned down to neutral.
Interaction types (likes, bookmarks, reposts, replies, photos) keep
their semantic colors unchanged.

Confab-Link: http://localhost:8080/sessions/bd3f7012-c703-47e9-bfe2-2ad04ce1842d

featured.njk

@@ -45,7 +45,7 @@ permalink: "featured/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNu
       {% elif hasPhotos %}
         {% set borderClass = "border-l-purple-400 dark:border-l-purple-500" %}
       {% else %}
-        {% set borderClass = "border-l-amber-400 dark:border-l-amber-500" %}
+        {% set borderClass = "border-l-surface-300 dark:border-l-surface-600" %}
       {% endif %}
 
     <li class="h-entry post-card border-l-[3px] {{ borderClass }}">