feat(shop-admin): manage flash-sale sessions and activity items

Add a flash-sale page where a shop user lists, creates, edits, and deletes its
own sessions and their SKU activity items, setting the fixed sale price,
currency, reserved stock, and per-customer limit. Expose it as a flash-sale
navigation entry beside the existing shop operations.

apps/shop-admin/locales-extra.ts

@@ -6,6 +6,7 @@ export const enExtra = {
   },
   nav: {
     coupons: "Coupons",
+    flashSales: "Flash sales",
   },
   shop: {
     dashboardTitle: "Merchant dashboard",
@@ -85,6 +86,37 @@ export const enExtra = {
     couponWindowInvalid: "End must not precede start.",
     enabledOn: "Enabled",
     enabledOff: "Disabled",
+    flashSaleList: "Flash sales",
+    newFlashSale: "New session",
+    editFlashSale: "Edit session",
+    flashLabelEn: "Label (English)",
+    flashLabelZh: "Label (中文)",
+    flashStartsAt: "Starts at",
+    flashEndsAt: "Ends at",
+    flashEnabled: "Enabled",
+    createFlashSale: "Create session",
+    updateFlashSale: "Update session",
+    flashSaleSaved: "Session saved.",
+    flashItemSaved: "Activity item saved.",
+    flashItems: "Activity items",
+    noFlashItems: "No activity items yet.",
+    newFlashItem: "Add activity item",
+    editFlashItem: "Edit activity item",
+    flashSku: "SKU",
+    flashSelectSku: "Select a SKU",
+    flashSalePrice: "Sale price (minor units)",
+    flashReservedStock: "Reserved stock",
+    flashPerCustomerLimit: "Per-customer limit",
+    saveFlashItem: "Save item",
+    flashOriginalPrice: "Catalog price",
+    flashSold: "Sold",
+    flashRemaining: "Remaining",
+    flashLabelRequired: "Both language labels are required.",
+    flashSkuRequired: "Choose a SKU.",
+    flashPriceInvalid: "Sale price must be a positive integer.",
+    flashStockInvalid: "Reserved stock cannot be negative.",
+    flashLimitInvalid: "Per-customer limit must be a positive integer.",
+    flashWindowInvalid: "End must not precede start.",
   },
 } as Record<string, unknown>;
 
@@ -94,6 +126,7 @@ export const zhExtra = {
   },
   nav: {
     coupons: "优惠券",
+    flashSales: "秒杀",
   },
   shop: {
     dashboardTitle: "商家仪表盘",
@@ -173,5 +206,36 @@ export const zhExtra = {
     couponWindowInvalid: "结束时间不能早于开始时间。",
     enabledOn: "已启用",
     enabledOff: "已停用",
+    flashSaleList: "秒杀活动",
+    newFlashSale: "新建场次",
+    editFlashSale: "编辑场次",
+    flashLabelEn: "标题（英文）",
+    flashLabelZh: "标题（中文）",
+    flashStartsAt: "开始时间",
+    flashEndsAt: "结束时间",
+    flashEnabled: "启用",
+    createFlashSale: "创建场次",
+    updateFlashSale: "更新场次",
+    flashSaleSaved: "场次已保存。",
+    flashItemSaved: "活动商品已保存。",
+    flashItems: "活动商品",
+    noFlashItems: "暂无活动商品。",
+    newFlashItem: "添加活动商品",
+    editFlashItem: "编辑活动商品",
+    flashSku: "SKU",
+    flashSelectSku: "请选择 SKU",
+    flashSalePrice: "秒杀价（最小单位）",
+    flashReservedStock: "活动库存",
+    flashPerCustomerLimit: "每人限购",
+    saveFlashItem: "保存商品",
+    flashOriginalPrice: "原价",
+    flashSold: "已售",
+    flashRemaining: "剩余",
+    flashLabelRequired: "中英文标题均为必填项。",
+    flashSkuRequired: "请选择 SKU。",
+    flashPriceInvalid: "秒杀价必须为正整数。",
+    flashStockInvalid: "活动库存不能为负数。",
+    flashLimitInvalid: "每人限购必须为正整数。",
+    flashWindowInvalid: "结束时间不能早于开始时间。",
   },
 } as Record<string, unknown>;