feat: 分站充值入口 + 邀请返佣 + 充值金额显示人民币

- 分站控制台新增充值 tab，复用主站 TopUp 组件
- 分站注册支持 aff_code 邀请码，走主站反佣逻辑
- 分站充值页新增邀请返佣卡片（邀请链接、佣金统计、划转、收入明细）
- 分站充值快捷按钮和输入框按汇率显示人民币
- 后端新增 5 个分站 aff API 路由，复用主站 controller

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/api.js

@@ -80,6 +80,13 @@ export const createCryptoOrder = (data) => api.post('/api/dist/topup/crypto/pay'
 export const getCryptoOrderStatus = (tradeNo) => api.get(`/api/dist/topup/crypto/status?trade_no=${tradeNo}`);
 export const getTopupHistory = (params) => api.get('/api/dist/topup/history', { params });
 
+// ===== Affiliate / Invitation =====
+export const getAffCode = () => api.get('/api/dist/aff');
+export const transferAffQuota = (data) => api.post('/api/dist/aff_transfer', data);
+export const getAffEarnings = (params) => api.get('/api/dist/aff_earnings', { params });
+export const getAffPayouts = (params) => api.get('/api/dist/aff_payouts', { params });
+export const requestAffWithdraw = (data) => api.post('/api/dist/aff_withdraw', data);
+
 // ===== Helpers =====
 export const quotaToDollar = (quota) => (quota / Q).toFixed(4);
 export const quotaToDollar6 = (quota) => (quota / Q).toFixed(6);