feat(auth): 登录注册找回绑定前台 1:1 壳层/文案/协议

抽出 sign.css，统一全页登录/注册与找回/绑定视觉；中文文案与用户协议契约对齐 Auth_Service；弹层字段与 logo 同步。

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

templates/pages/page-reset-password.php

@@ -54,13 +54,19 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['aksrt_action']) && $_
     }
 }
 
+remove_action('wp_footer', 'aksrt_render_footer_tabbar', 20);
+remove_action('wp_footer', 'aksrt_render_float_buttons', 30);
+add_filter('body_class', static function ($classes) {
+	$classes[] = 'page-template-user-sign';
+	return $classes;
+});
 get_header();
 ?>
 
 <main id="main-content" class="site-main" tabindex="-1">
 	<div class="auth-shell">
 		<div class="auth-card">
-			<div class="auth-card__logo" aria-hidden="true">AK</div>
+			<div class="auth-card__logo sign-logo" aria-hidden="true"><?php if (function_exists('aksrt_get_auth_sign_logo_html')) { echo aksrt_get_auth_sign_logo_html(); } else { echo 'AK'; } // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped ?></div>
 			<h1 class="auth-card__title"><?php bloginfo('name'); ?></h1>
 
 			<?php if ($mode === 'success') : ?>