优化手工开票日期选择器国际化

client/src/i18n/locales/en-US.ts

@@ -283,6 +283,7 @@ export default {
     departureDate: 'Departure date',
     roomRateNote: 'Room rate note',
     roomRateNotePlaceholder: 'e.g. including BF',
+    datePlaceholder: 'yyyy-mm-dd',
     extraBedRate: 'Extra bed rate',
     description: 'Description',
     roomType: 'Room type',

client/src/i18n/locales/th-TH.ts

@@ -283,6 +283,7 @@ export default {
     departureDate: 'Departure Date',
     roomRateNote: 'Room Rate Note',
     roomRateNotePlaceholder: 'เช่น including BF',
+    datePlaceholder: 'yyyy-mm-dd',
     extraBedRate: 'Extra Bed Rate',
     description: 'Description',
     roomType: 'Room Type',

client/src/i18n/locales/zh-CN.ts

@@ -283,6 +283,7 @@ export default {
     departureDate: '离店日期（Departure Date）',
     roomRateNote: '房价备注（Room Rate Note）',
     roomRateNotePlaceholder: '例如 including BF',
+    datePlaceholder: '年-月-日',
     extraBedRate: '加床价格（Extra Bed Rate）',
     description: '费用描述（Description）',
     roomType: '房型（Room Type）',