feat(05-01): create archive query helper for Elementor integration

Add DDHH_JM_Archive class to modify job archive queries. Ensures
Elementor Loop Grid displays only published jobs sorted by date
(newest first) with no pagination limit.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

includes/class-ddhh-job-manager.php

@@ -65,6 +65,9 @@ class DDHH_JM_Job_Manager {
 		// Initialize notifications
 		add_action( 'init', array( 'DDHH_JM_Notifications', 'setup_hooks' ) );
 
+		// Initialize archive query helper
+		add_action( 'init', array( 'DDHH_JM_Archive', 'setup_hooks' ) );
+
 		// Initialize admin UI enhancements (admin-only)
 		if ( is_admin() ) {
 			add_action( 'init', array( 'DDHH_JM_Admin_UI', 'setup_hooks' ) );