✨feature: Implement project-type taxonomy archive template and enhance breadcrumb navigation

lib/class-breadcrumbs.php

@@ -46,7 +46,11 @@ class Breadcrumbs {
 			// Static Page - add the parent pages if any, and the page title
 			$breadcrumbs = array_merge( $breadcrumbs, self::getStaticPageBreadcrumbs( $post ) );
 		} elseif ( is_category() || is_tag() || is_tax() ) {
-			// Taxonomy Archive - add the taxonomy term name
+			// Taxonomy Archive - if this is a project-type term, surface the
+			// Projects archive as a clickable parent in the trail.
+			if ( is_tax( 'project-type' ) ) {
+				$breadcrumbs[] = self::getProjectsArchiveLinkBreadcrumb();
+			}
 			$breadcrumbs[] = self::getTaxonomyArchiveBreadcrumb();
 		} elseif ( is_post_type_archive() ) {
 			// Post Type Archive - add the post type name
@@ -205,6 +209,24 @@ class Breadcrumbs {
 		return $postType ? array( 'label' => $postType->labels->name ) : array();
 	}
 
+	/** Generates a clickable Projects archive breadcrumb.
+	 *
+	 * Used in the taxonomy archive trail so users have a working "back to
+	 * all projects" link in the breadcrumb. Distinct from
+	 * getPostTypeArchiveBreadcrumb(), which omits the URL because on the
+	 * post-type archive itself that crumb is the active leaf and shouldn't
+	 * link to itself.
+	 *
+	 * @return array Breadcrumb data with both label and url.
+	 */
+	private static function getProjectsArchiveLinkBreadcrumb() {
+		$url = get_post_type_archive_link( 'projects' );
+		return array(
+			'url'   => $url ? $url : '',
+			'label' => __( 'Projects', 'ks-portfolio' ),
+		);
+	}
+
 	/** Generates breadcrumbs for date-based archives.
 	 *
 	 * This method is responsible for creating breadcrumb navigation