refactor(finance): 清理 legacy_platform 的展示与死查询

- 未归一组统计默认渠道补上 third_party_voucher，移除已无数据的 legacy_platform
- 前端移除历史归档/历史平台的类型与标签
- 保留后端口径的 legacy_platform→archived 筛选别名，旧链接不报错

apps/frontend/src/pages/admin/AdminSalesProfitPage.tsx

@@ -48,7 +48,6 @@ const FULFILLMENT_MODE_LABEL: Record<string, string> = {
   work_order: '接单平台',
   affiliate_dash: '自动发货',
   third_party_voucher: '第三方卡券',
-  legacy_platform: '历史归档',
   manual: '人工客服',
   archived: '历史归档',
   unclassified: '未分类',

apps/frontend/src/pages/admin/cost-center/CostExceptionPanel.tsx

@@ -40,7 +40,6 @@ import { CostPreviewModal } from './CostPreviewModal'
 const FULFILLMENT_MODE_TAG_COLORS: Record<string, string> = {
   work_order: 'blue',
   affiliate_dash: 'green',
-  legacy_platform: 'default',
   manual: 'orange',
 }
 

apps/frontend/src/pages/admin/cost-center/CostPreviewModal.tsx

@@ -19,7 +19,6 @@ import { costModelLabel, providerLabel } from './shared'
 const FULFILLMENT_MODE_LABELS: Record<string, string> = {
   work_order: '接单平台',
   affiliate_dash: '自动发货',
-  legacy_platform: '历史平台',
   manual: '人工客服',
 }
 

apps/frontend/src/pages/admin/cost-center/shared.ts

@@ -129,7 +129,6 @@ export const FULFILLMENT_MODE_LABELS: Record<string, string> = {
   work_order: '接单平台',
   affiliate_dash: '自动发货',
   third_party_voucher: '第三方卡券',
-  legacy_platform: '历史归档',
   manual: '人工客服',
   archived: '历史归档',
   unclassified: '未分类',
@@ -139,7 +138,6 @@ export const FULFILLMENT_MODE_COLORS: Record<string, string> = {
   work_order: 'blue',
   affiliate_dash: 'green',
   third_party_voucher: 'cyan',
-  legacy_platform: 'default',
   manual: 'orange',
   archived: 'default',
   unclassified: 'gold',