test(account): stub do_action in the account settings harness

The email-change flow fires jio_user_email_changed after a successful
write, but the harness only shimmed add_action, so the run died on an
undefined do_action() before reaching the assertions.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/widget-system/account-settings-harness.php

@@ -12,6 +12,7 @@ namespace {
 	$GLOBALS['jio_account_meta'] = [];
 	$GLOBALS['jio_account_transients'] = [];
 	$GLOBALS['jio_account_actions'] = [];
+	$GLOBALS['jio_account_actions_fired'] = [];
 	$GLOBALS['jio_account_mail'] = [];
 	$GLOBALS['jio_account_existing_emails'] = [];
 	$GLOBALS['jio_account_captcha_calls'] = [];
@@ -45,6 +46,10 @@ namespace {
 	function add_action(string $hook, callable $callback): void {
 		$GLOBALS['jio_account_actions'][$hook] = $callback;
 	}
+	/** jQuery-free stub: record fired hooks so tests can assert side effects. */
+	function do_action(string $hook, mixed ...$args): void {
+		$GLOBALS['jio_account_actions_fired'][] = ['hook' => $hook, 'args' => $args];
+	}
 	function __(string $text, string $domain = ''): string { return $text; }
 	function is_wp_error(mixed $value): bool { return $value instanceof WP_Error; }
 	function is_email(string $email): bool { return (bool) filter_var($email, FILTER_VALIDATE_EMAIL); }