Release 0.1.6 — fix AJAX step-save listeners never attaching (hc-5yy)

The 0.1.5 auto-save never fired: the inline <script> is emitted before the
step cards in the markup, so document.querySelectorAll('form.att-hc-step-save')
ran at parse time against a DOM with no forms yet and attached no listeners —
changing status or blurring notes produced no request at all.

The pre-existing step-history loader had the identical latent defect (its
"Previous notes" expander was also dead on live for the same reason).

Fix: both inline scripts now defer their querySelectorAll wiring to
DOMContentLoaded, so it runs after the cards are parsed. No reordering of the
markup, so the <style> blocks stay put and there's no flash of unstyled UI.

Bumps header, ATT_HC_VERSION and updates.json so PUC offers it to the sites
already on the broken 0.1.5. Plugin-only; server untouched.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

att-site-healthcheck.php

@@ -2,7 +2,7 @@
 /**
  * Plugin Name: ATT Site Healthcheck
  * Description: Walks a technician through a structured WordPress site healthcheck. Steps are drop-in PHP files so adding/removing one is a single file change.
- * Version:     0.1.5
+ * Version:     0.1.6
  * Author:      Steve Hanlon
  * License:     Proprietary
  * License URI: https://git.h12e.com/steve/wp-healthcheck/raw/branch/main/LICENSE
@@ -15,7 +15,7 @@ if (!defined('ABSPATH')) {
     exit;
 }
 
-define('ATT_HC_VERSION', '0.1.5');
+define('ATT_HC_VERSION', '0.1.6');
 define('ATT_HC_PLUGIN_FILE', __FILE__);
 define('ATT_HC_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('ATT_HC_PLUGIN_URL', plugin_dir_url(__FILE__));