Add Toolbar proxy notice for Atomic sites (#38519)

* Add profile-settings-notices file

* Update copy

* changelog

* Add translation

* Update copy

projects/packages/jetpack-mu-wpcom/changelog/add-profile-toolbar-notice

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Add a12n notice about proxied toolbar

projects/packages/jetpack-mu-wpcom/src/class-jetpack-mu-wpcom.php

@@ -92,15 +92,16 @@ public static function load_features() {
 		require_once __DIR__ . '/features/error-reporting/error-reporting.php';
 		require_once __DIR__ . '/features/first-posts-stream/first-posts-stream-helpers.php';
 		require_once __DIR__ . '/features/font-smoothing-antialiased/font-smoothing-antialiased.php';
+		require_once __DIR__ . '/features/google-analytics/google-analytics.php';
 		require_once __DIR__ . '/features/import-customizations/import-customizations.php';
 		require_once __DIR__ . '/features/marketplace-products-updater/class-marketplace-products-updater.php';
 		require_once __DIR__ . '/features/media/heif-support.php';
 		require_once __DIR__ . '/features/site-editor-dashboard-link/site-editor-dashboard-link.php';
 		require_once __DIR__ . '/features/wpcom-admin-dashboard/wpcom-admin-dashboard.php';
 		require_once __DIR__ . '/features/wpcom-block-editor/class-jetpack-wpcom-block-editor.php';
 		require_once __DIR__ . '/features/wpcom-block-editor/functions.editor-type.php';
+		require_once __DIR__ . '/features/wpcom-profile-settings/profile-settings-notices.php';
 		require_once __DIR__ . '/features/wpcom-themes/wpcom-theme-fixes.php';
-		require_once __DIR__ . '/features/google-analytics/google-analytics.php';
 
 		// Initializers, if needed.
 		\Marketplace_Products_Updater::init();

projects/packages/jetpack-mu-wpcom/src/features/wpcom-profile-settings/profile-settings-notices.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * Custom notices for wp-admin/profile.php
+ *
+ * @package automattic/jetpack-mu-wpcom
+ */
+
+/**
+ * Adds a notice for Automatticians informing them that the Toolbar always shows on the front end on Atomic sites if
+ * they are connected to Autoproxxy.
+ */
+function maybe_show_wpcom_toolbar_proxy_notice() {
+	$is_proxied = isset( $_SERVER['A8C_PROXIED_REQUEST'] )
+			? sanitize_text_field( wp_unslash( $_SERVER['A8C_PROXIED_REQUEST'] ) )
+			: defined( 'A8C_PROXIED_REQUEST' ) && A8C_PROXIED_REQUEST;
+	$is_atomic  = defined( 'IS_ATOMIC' ) && IS_ATOMIC;
+
+	if ( $is_proxied && $is_atomic ) {
+		?>
+		<style>
+			.toolbar-autoproxxy-notice {
+				color: #666;
+				font-style: italic;
+				margin-top: 5px;
+			}
+		</style>
+		<script type="text/javascript">
+			document.addEventListener('DOMContentLoaded', function () {
+				// Find the Toolbar checkbox label container using the unique ID.
+				var toolbarCheckboxLabel = document.querySelector('#admin_bar_front').parentNode;
+				if (toolbarCheckboxLabel) {
+					// Create a new div for the notice.
+					var newDiv = document.createElement('div');
+					newDiv.className = 'toolbar-autoproxxy-notice';
+					newDiv.textContent = '<?php echo esc_js( __( 'The Toolbar is always visible on Atomic sites while connected to the Automattic proxy.', 'jetpack-mu-wpcom' ) ); ?>'
+
+					// Insert the new div after the checkbox and label.
+					toolbarCheckboxLabel.appendChild(newDiv);
+
+					// Find and remove the <br> tag following the label to improve spacing.
+					var brElement = toolbarCheckboxLabel.nextSibling;
+					if (brElement && brElement.tagName === 'BR') {
+						brElement.parentNode.removeChild(brElement);
+					}
+				}
+			});
+		</script>
+		<?php
+	}
+}
+
+add_action( 'admin_footer-profile.php', 'maybe_show_wpcom_toolbar_proxy_notice' );