Restyle category tree to idiomatic Bootstrap list-group pattern (v0.1.8)

Switch from custom link classes to Bootstrap's native list-group-item-action
pattern. Replace bold primary-colored active background with subtle tertiary
background, left accent border, and semibold text.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

templates/global/category-tree.html.twig

@@ -1,13 +1,13 @@
 {#
  # Product Category Tree (Bootstrap 5)
  #
- # Renders a hierarchical product category navigation with collapsible
- # sub-levels, up to 3 levels deep. Uses Bootstrap 5 list-group and
- # collapse components for responsive tree navigation.
+ # Renders a hierarchical product category navigation using Bootstrap
+ # list-group with nested sub-lists and action links.
  #
  # Expected context:
- #   categories - Hierarchical array from wc_bootstrap_get_category_tree()
- #   shop_url   - URL to the main shop page
+ #   categories  - Hierarchical array from wc_bootstrap_get_category_tree()
+ #   shop_url    - URL to the main shop page
+ #   current_cat - Term ID of the currently viewed category (0 = shop page)
  #
  # @package WcBootstrap
  # @since 0.1.7
@@ -19,16 +19,14 @@
         {{ __('Categories', 'wc-bootstrap') }}
     </h3>
 
-    <ul class="list-group list-group-flush category-tree">
-        <li class="list-group-item px-0 py-1">
-            <a href="{{ shop_url }}"
-               class="category-tree-link d-block text-decoration-none py-1 px-2 rounded{% if current_cat == 0 %} active fw-semibold{% endif %}">
-                {{ __('All products', 'wc-bootstrap') }}
-            </a>
-        </li>
+    <div class="list-group list-group-flush category-tree">
+        <a href="{{ shop_url }}"
+           class="list-group-item list-group-item-action border-0 px-2 py-1{% if current_cat == 0 %} active{% endif %}">
+            {{ __('All products', 'wc-bootstrap') }}
+        </a>
         {% for cat in categories %}
             {% include 'global/category-tree-node.html.twig' with { node: cat, level: 1 } only %}
         {% endfor %}
-    </ul>
+    </div>
 </nav>
 {% endif %}