✨ refactor(wallet): Top-up layout to embed subscription plans into the recharge card tabs

- Defaulting to subscriptions when available and avoiding initial flash when no plans exist.
- Adjust the wide-screen layout to place wallet and invite sections side by side, simplify the subscription header and controls, and add padding to prevent card borders from clipping.
- Update related i18n strings by adding the new tab label and removing the obsolete subscription blurb.

web/src/i18n/locales/en.json

@@ -2721,7 +2721,7 @@
     "绑定订阅套餐": "Bind Subscription Plan",
     "绑定后会立即生成用户订阅（无需支付），有效期按套餐配置计算。": "After binding, a user subscription is created immediately (no payment required); validity follows the plan configuration.",
     "订阅套餐": "Subscription Plans",
-    "购买订阅获得模型额度/次数": "Purchase a subscription to get model quota/usage",
+    "额度充值": "Quota Top-up",
     "优先订阅": "Subscription first",
     "优先钱包": "Wallet first",
     "仅用订阅": "Subscription only",