feat(vip): restructure membership settings into structured groups

Replace the pipe-delimited VIP configuration with structured groups and
accordions, matching the reference theme (Zibll) 1:1.

Settings:
- 会员等级 keeps only the nav buttons and the two level switches, plus the
  "must enable level 1 first" guard. Level identity fields (display name,
  intro, benefits HTML, icon) and 会员商品 move into the 一级会员/二级会员
  tabs of 会员购买选项, so each level is configured in one place.
- Level tab titles bind to the configured display name via a new
  titleKey/titleFallback hook in AksFormRenderer.
- 会员商品 is a repeater with exactly the reference fields: 执行价/原价/
  促销标签/标签颜色/会员有效时间/时长单位. The tag colour uses the full
  b+jb palette and now reaches the product card instead of a hardcoded
  jb-yellow.
- 会员续费 gains the 自定义商品 type backed by per-level renew-product
  groups; the discount becomes a 0.1-9.9 slider with float sanitizing.
- 会员升级 becomes the reference three-block accordion (month-to-month
  day-rate, jump to permanent, permanent to permanent), each with its own
  price, strikethrough price, promo tag and tag colour.
- 积分兑换明细 is a repeater (points/level/duration/unit) where the
  duration accepts the literal Permanent.

Runtime:
- PaymentRuntime normalizes the structured groups into purchasable rows
  (money normalization, palette validation, zero-price and out-of-range
  rows dropped) and no longer emits any *_raw strings.
- The catalog builder carries tag_class through and routes renewals to the
  renew-product group under 自定义商品.
- The points-exchange order note carries time/unit so month durations use
  calendar math instead of a 30-day approximation.

Dead code removed: parse_level_products, parse_packages,
parse_upgrade_product_line and their pipe-splitting, plus nine zero-call
PaymentRuntime proxy methods in HomeCms. No dual-format or migration path
was added; SchemaProvider already falls back to defaults when a stored
group value is not an array, so existing pipe strings degrade safely.

Verified: php -l on every changed PHP file, 655 Node contract tests passing
(14 new ones in vip-settings-structured-contract.test.cjs exercising the
real schema build and runtime normalization via a PHP harness), and the
admin SPA builds.

inc/helpers/user-center-renderers/vip-tab.php

@@ -29,6 +29,8 @@ $vip_state_name = (string) ($vip_state['state'] ?? 'unopened');
 $vip_state_source = (string) ($vip_state['source'] ?? 'none');
 $levels = is_array($vip_settings['levels'] ?? null) ? $vip_settings['levels'] : [];
 $desc_top = (string) ($vip_settings['desc'] ?? '');
+$renew_desc = (string) ($vip_settings['renew']['desc'] ?? '');
+$upgrade_desc = (string) ($vip_settings['upgrade']['desc'] ?? '');
 
 // Membership summary: title → level → intro → expiry.
 $vip_state          = 'unopened';
@@ -116,6 +118,9 @@ foreach ([1, 2] as $lv) {
 		: '';
 	$cta      = sprintf(__('开通%s', 'aksrt'), $lv_name);
 	$vip_attr = $lv;
+	// 参考主题 zibpay_get_vip_card：续费/升级档位卡展示各自的一句话简介。
+	$card_action = 'pay';
+	$card_desc   = $lv_desc;
 	$lv_icon_url = esc_url((string) ($levels[$lv]['img_icon'] ?? ''));
 	$lv_icon = $lv_icon_url !== ''
 		? '<img' . aksrt_get_lazy_attr('lazy_other', $lv_icon_url, 'aksrt-vip-level-icon') . ' alt="" decoding="async">'
@@ -124,8 +129,10 @@ foreach ([1, 2] as $lv) {
 		$renew_lv = (int) substr($btn_type, 6);
 		if ($lv === $renew_lv) {
 			$cta = sprintf(__('续费%s', 'aksrt'), $lv_name);
+			$card_action = 'renew';
 		} elseif ($lv > $renew_lv) {
 			$cta = sprintf(__('升级%s', 'aksrt'), $lv_name);
+			$card_action = 'upgrade';
 		} else {
 			continue;
 		}
@@ -134,19 +141,26 @@ foreach ([1, 2] as $lv) {
 			continue;
 		}
 		$cta = sprintf(__('升级%s', 'aksrt'), $lv_name);
+		$card_action = 'upgrade';
 		$vip_attr = 2;
 	} elseif ($level > 0 && $lv < $level) {
 		continue;
 	} elseif ($level > 0 && $lv === $level) {
 		$cta = sprintf(__('续费%s', 'aksrt'), $lv_name);
+		$card_action = 'renew';
+	}
+	if ($card_action === 'renew' && $renew_desc !== '') {
+		$card_desc = $renew_desc;
+	} elseif ($card_action === 'upgrade' && $upgrade_desc !== '') {
+		$card_desc = $upgrade_desc;
 	}
 
 	$cards .= '<div class="aksrt-panel text-center pay-vip-info flex1 level-' . $lv . ' uc-vip-level-card">';
 	$cards .= '<div class="relative uc-vip-level-card__inner">';
 	$cards .= '<div class="v-iconbox mb10">';
 	$cards .= '<div class="v-name font-bold"><span class="v-icon">' . $lv_icon . '</span>' . esc_html($lv_name) . '</div>';
-	if ($lv_desc !== '') {
-		$cards .= '<div class="v-desc em09 muted-2-color">' . esc_html($lv_desc) . '</div>';
+	if ($card_desc !== '') {
+		$cards .= '<div class="v-desc em09 muted-2-color">' . esc_html($card_desc) . '</div>';
 	}
 	$cards .= '</div>';
 	$cards .= $equity;