Address code review feedback with improved comments

Co-authored-by: katsar0v <7236157+katsar0v@users.noreply.github.com>

Author: Copilot

includes/Admin/class-admin.php

@@ -582,6 +582,7 @@ public function render_dashboard_widget(): void {
 		global $wpdb;
 
 		// Get queue statistics.
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Static query with no user input, caching not needed for dashboard widget.
 		$queue_stats = $wpdb->get_row(
 			"SELECT 
 				SUM(CASE WHEN status = 'pending' THEN 1 ELSE 0 END) as pending,

includes/services/class-cron-handler.php

@@ -54,10 +54,11 @@ public function init() {
 	public function process_queue() {
 		global $wpdb;
 
-		// Record the last cron run timestamp.
+		// Record the cron run timestamp at the start of processing.
+		// This indicates when the cron was last triggered, useful for verifying cron health.
 		update_option( 'mskd_last_cron_run', time() );
 
-		// First, recover stuck emails (processing for too long)
+		// First, recover stuck emails (processing for too long).
 		$this->recover_stuck_emails();
 
 		// Get the configured batch size (emails per minute).