feat(shop-admin): manage shop coupon templates

Add a coupons page where a shop user lists, creates, edits, enables/disables,
and deletes only its own templates, with localized titles, minor-unit discount
and threshold, currency, claim stock, and an active window. Expose it as a
coupons navigation entry beside the existing shop operations.

apps/shop-admin/locales-extra.ts

@@ -4,6 +4,9 @@ export const enExtra = {
   auth: {
     shopRoleError: "This account is not authorized for the merchant console.",
   },
+  nav: {
+    coupons: "Coupons",
+  },
   shop: {
     dashboardTitle: "Merchant dashboard",
     profile: "Shop profile",
@@ -59,6 +62,29 @@ export const enExtra = {
     issueInvoice: "Issue invoice",
     taxNo: "Tax number",
     kind: "Type",
+    couponList: "Coupons",
+    newCoupon: "New coupon",
+    editCoupon: "Edit coupon",
+    couponTitleEn: "Title (English)",
+    couponTitleZh: "Title (中文)",
+    couponAmount: "Discount (minor units)",
+    couponThreshold: "Minimum spend (minor units)",
+    couponCurrency: "Currency",
+    couponStock: "Claim stock",
+    couponEnabled: "Enabled",
+    couponStartsAt: "Starts at",
+    couponEndsAt: "Ends at",
+    createCoupon: "Create coupon",
+    updateCoupon: "Update coupon",
+    couponSaved: "Coupon saved.",
+    couponDeleted: "Coupon deleted.",
+    couponTitleRequired: "Both language titles are required.",
+    couponAmountInvalid: "Discount must be a positive integer.",
+    couponThresholdInvalid: "Minimum spend cannot be negative.",
+    couponStockInvalid: "Claim stock cannot be negative.",
+    couponWindowInvalid: "End must not precede start.",
+    enabledOn: "Enabled",
+    enabledOff: "Disabled",
   },
 } as Record<string, unknown>;
 
@@ -66,6 +92,9 @@ export const zhExtra = {
   auth: {
     shopRoleError: "此账号无权访问商家控制台。",
   },
+  nav: {
+    coupons: "优惠券",
+  },
   shop: {
     dashboardTitle: "商家仪表盘",
     profile: "店铺信息",
@@ -121,5 +150,28 @@ export const zhExtra = {
     issueInvoice: "开具发票",
     taxNo: "税号",
     kind: "类型",
+    couponList: "优惠券",
+    newCoupon: "新建优惠券",
+    editCoupon: "编辑优惠券",
+    couponTitleEn: "标题（英文）",
+    couponTitleZh: "标题（中文）",
+    couponAmount: "优惠金额（最小单位）",
+    couponThreshold: "使用门槛（最小单位）",
+    couponCurrency: "币种",
+    couponStock: "可领取库存",
+    couponEnabled: "启用",
+    couponStartsAt: "开始时间",
+    couponEndsAt: "结束时间",
+    createCoupon: "创建优惠券",
+    updateCoupon: "更新优惠券",
+    couponSaved: "优惠券已保存。",
+    couponDeleted: "优惠券已删除。",
+    couponTitleRequired: "中英文标题均为必填项。",
+    couponAmountInvalid: "优惠金额必须为正整数。",
+    couponThresholdInvalid: "使用门槛不能为负数。",
+    couponStockInvalid: "可领取库存不能为负数。",
+    couponWindowInvalid: "结束时间不能早于开始时间。",
+    enabledOn: "已启用",
+    enabledOff: "已停用",
   },
 } as Record<string, unknown>;