fix(user-center): replicate reference theme sidebar icons via SVG sprite

The user-center sidebar rendered Font Awesome glyphs while the reference theme
paints multi-tone inline SVGs, and several glyphs were simply wrong for their
slot: fa-chart-line served both 我的等级 and 推广收益, fa-money-bill served both
余额 and 积分, and fa-pen stood in for 创作收益.

The theme already ships every sprite key the reference sidebar needs in
assets/js/runtime/svg-icon.js, and main.min.js injects the <symbol id="icon-*">
set on every frontend page, so no new icon system was needed. The two grids now
use the reference theme's icon-but-box / user-icon-but-box shell (four per row,
em16 icon, 12px muted label) in place of AKSRT's tinted 38px pill, and every
remaining sidebar glyph and arrow resolves through aksrt_icon_markup():

  我的服务  我的等级 trend-color, 官方认证 user-auth, 我的订单 order-color
  功能设置  消息通知 msg-color, 个人资料 user-color, 账户安全 security-color
  资产卡    余额 money-color-2, 积分 points-color
  中心卡    创作收益 merchant-color, 推广收益 money-color
  其它      VIP 入口 vip_1, 抽屉触发器 menu, 箭头统一 right

Dead code went with the swap: the whole .uc-service-grid block including the
unused --cart and --revenue tones, the count badge (no caller ever set count),
and the tone key. The two card selectors that targeted <i> now also cover <svg>
so the icon sizes survive the element change, and the VIP arrow keeps
uc-sidebar-vip__arrow for its hover animation. level/profile/settings gained
their missing tab keys, which completes the icon-but-* class names and lets the
existing .is-active sync cover all six entries.

Verification: node --test across widget-system, navigation, admin,
asset-ledger, dev, front-submit and fixtures (620 tests), plus php -l on the
five changed PHP files. Contract-locked in
tests/widget-system/user-center-sidebar-icons-contract.test.cjs.

inc/helpers/user-center-renderers/sidebar-nav.php

@@ -2,6 +2,9 @@
 /**
  * User center sidebar: services and account settings.
  *
+ * Icon set mirrors the reference theme user-center sidebar: every entry renders
+ * an inline SVG from the theme sprite through aksrt_icon_markup().
+ *
  * @package AKSRT
  */
 
@@ -17,22 +20,20 @@ $orders_url = $orders_available ? (string) ($orders_url ?? '') : '';
 $services = array_values(array_filter([
 	[
 		'label' => __('我的等级', 'aksrt'),
-		'icon'  => 'chart-line',
-		'tone'  => 'level',
+		'icon'  => 'trend-color',
 		'url'   => $level_url,
+		'tab'   => 'level',
 	],
 
 	[
 		'label' => __('官方认证', 'aksrt'),
-		'icon'  => 'id-badge',
-		'tone'  => 'auth',
+		'icon'  => 'user-auth',
 		'url'   => $auth_url,
 		'tab'   => 'auth',
 	],
 	[
 		'label' => __('我的订单', 'aksrt'),
-		'icon'  => 'receipt',
-		'tone'  => 'orders',
+		'icon'  => 'order-color',
 		'url'   => $orders_url,
 		'tab'   => 'orders',
 	],
@@ -41,35 +42,38 @@ $services = array_values(array_filter([
 $settings = array_values(array_filter([
 	[
 		'label' => __('消息通知', 'aksrt'),
-		'icon'  => 'bell',
-		'tone'  => 'notice',
+		'icon'  => 'msg-color',
 		'url'   => isset($dashboard_tabs['msg']) ? aksrt_get_user_center_tab_url('msg') : '',
 		'tab'   => 'msg',
 	],
 	[
 		'label' => __('个人资料', 'aksrt'),
-		'icon'  => 'user-edit',
-		'tone'  => 'profile',
+		'icon'  => 'user-color',
 		'url'   => isset($dashboard_tabs['profile']) ? aksrt_get_user_center_tab_url('profile') : '',
+		'tab'   => 'profile',
 	],
 	[
 		'label' => __('账户安全', 'aksrt'),
-		'icon'  => 'shield-alt',
-		'tone'  => 'security',
+		'icon'  => 'security-color',
 		'url'   => isset($dashboard_tabs['settings']) ? aksrt_get_user_center_tab_url('settings') : '',
+		'tab'   => 'settings',
 	],
 ], static fn(array $item): bool => (string) $item['url'] !== ''));
 
 $render_grid = static function (array $items): void {
 	?>
-	<div class="uc-service-grid">
-		<?php foreach ($items as $item) : ?>
-			<a class="uc-service-grid__item uc-service-grid__item--<?php echo esc_attr((string) $item['tone']); ?><?php echo !empty($item['tab']) && ($active_tab ?? '') === $item['tab'] ? ' is-active' : ''; ?>" href="<?php echo esc_url((string) $item['url']); ?>"<?php if (!empty($item['tab'])) : ?> data-tab="<?php echo esc_attr((string) $item['tab']); ?>"<?php endif; ?>>
-				<span class="uc-service-grid__icon">
-					<i class="fa fas fa-<?php echo esc_attr((string) $item['icon']); ?>" aria-hidden="true"></i>
-					<?php if (!empty($item['count'])) : ?><small><?php echo esc_html((string) $item['count']); ?></small><?php endif; ?>
-				</span>
-				<span><?php echo esc_html((string) $item['label']); ?></span>
+	<div class="flex ac hh text-center icon-but-box user-icon-but-box">
+		<?php foreach ($items as $item) :
+			$tab = (string) ($item['tab'] ?? '');
+			$item_class = 'icon-but-' . ($tab !== '' ? $tab : 'item');
+			if (($active_tab ?? '') === $tab) {
+				$item_class .= ' is-active';
+			}
+			$icon_html = aksrt_icon_markup('zibsvg-' . (string) $item['icon']);
+		?>
+			<a class="<?php echo esc_attr($item_class); ?>" href="<?php echo esc_url((string) $item['url']); ?>"<?php if ($tab !== '') : ?> data-tab="<?php echo esc_attr($tab); ?>"<?php endif; ?>>
+				<div class="em16"><?php echo $icon_html; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped ?></div>
+				<div class="px12 muted-color mt3"><?php echo esc_html((string) $item['label']); ?></div>
 			</a>
 		<?php endforeach; ?>
 	</div>