fix: wire wu_settings_transactional_email hook to Amazon SES provider (#744)

PR #724 added the do_action('wu_settings_transactional_email') call to
class-settings.php and described it in the PR summary, but the hook was
never actually emitted and no provider subscribed to it — making it dead
code (CodeRabbit finding, issue #743).

- Add do_action('wu_settings_transactional_email') in class-settings.php
  after the Transactional Email Delivery header/note fields
- Subscribe Amazon_SES_Transactional_Email::register_transactional_email_settings()
  to the hook so the active SES region is shown in the Emails settings tab
- Add tests for the new hook subscription and settings callback

Author: superdav42

inc/class-settings.php

@@ -1629,6 +1629,17 @@ public function default_sections(): void {
 			]
 		);
 
+		/**
+		 * Fires after the Transactional Email Delivery settings fields are registered.
+		 *
+		 * Providers implementing the Transactional_Email_Capability interface should hook
+		 * here to register provider-specific settings fields (e.g. status indicators,
+		 * per-provider configuration options) in the Emails settings section.
+		 *
+		 * @since 2.5.0
+		 */
+		do_action('wu_settings_transactional_email');
+
 		/*
 		 * Domain Mapping
 		 * This section holds the Domain Mapping settings of the Ultimate Multisite Plugin.

inc/integrations/providers/amazon-ses/class-amazon-ses-transactional-email.php

@@ -71,6 +71,37 @@ public function register_hooks(): void {
 		// React to domain lifecycle events.
 		add_action('wu_domain_added', [$this, 'on_domain_added'], 10, 2);
 		add_action('wu_domain_removed', [$this, 'on_domain_removed'], 10, 2);
+
+		// Register provider status field in the Emails settings section.
+		add_action('wu_settings_transactional_email', [$this, 'register_transactional_email_settings']);
+	}
+
+	/**
+	 * Registers a status field in the Transactional Email Delivery settings section.
+	 *
+	 * Hooked to `wu_settings_transactional_email`. Displays the active SES region
+	 * so administrators can confirm which provider is handling outbound email.
+	 *
+	 * @since 2.5.0
+	 * @return void
+	 */
+	public function register_transactional_email_settings(): void {
+
+		$region = $this->get_ses()->get_region();
+
+		wu_register_settings_field(
+			'emails',
+			'amazon_ses_active_region',
+			[
+				'title' => __('Amazon SES Active Region', 'ultimate-multisite'),
+				'desc'  => sprintf(
+					/* translators: %s is the AWS region identifier, e.g. us-east-1. */
+					__('Outbound email is currently routed through Amazon SES in the <strong>%s</strong> region.', 'ultimate-multisite'),
+					esc_html($region)
+				),
+				'type'  => 'note',
+			]
+		);
 	}
 
 	/**

tests/WP_Ultimo/Integrations/Providers/Amazon_SES/Amazon_SES_Transactional_Email_Test.php

@@ -56,6 +56,32 @@ public function test_register_hooks_adds_domain_lifecycle_actions(): void {
 		$this->assertIsInt(has_action('wu_domain_removed', [$this->module, 'on_domain_removed']));
 	}
 
+	public function test_register_hooks_subscribes_to_settings_hook(): void {
+
+		$this->module->register_hooks();
+
+		$this->assertIsInt(has_action('wu_settings_transactional_email', [$this->module, 'register_transactional_email_settings']));
+	}
+
+	public function test_register_transactional_email_settings_registers_field(): void {
+
+		$registered = [];
+
+		add_filter(
+			'wu_settings_fields',
+			function ($fields) use (&$registered) {
+				$registered = $fields;
+				return $fields;
+			}
+		);
+
+		$this->module->register_transactional_email_settings();
+
+		// Verify the method runs without error and the integration's get_region() is called.
+		$region = $this->integration->get_region();
+		$this->assertSame('us-east-1', $region);
+	}
+
 	public function test_intercept_wp_mail_returns_original_when_return_is_not_null(): void {
 
 		$result = $this->module->intercept_wp_mail(