Add restore functionality for template management and enhance related components

Implemented a new endpoint for restoring templates to their last applied state, allowing users to revert changes made since the last application. Updated the ScheduleTemplate class to include a snapshot of the last applied state, enabling rollback capabilities. Enhanced the frontend with a restore button in the ChannelDetail component, providing users with a confirmation prompt before executing the restore action. Localization updates were made to support new UI strings in both English and Russian, improving the overall user experience in template management.

frontend/src/features/admin/channels/api.ts

@@ -20,6 +20,7 @@ import type {
   JunctionTemplateDto,
   LayerApplicability,
   PlanningRules,
+  RestoreTemplateResultDto,
   ScheduleDiffDto,
   ScheduleEntryDto,
   SchedulePreviewDto,
@@ -84,6 +85,16 @@ export function applyChannelTemplate(channelId: string) {
   })
 }
 
+/**
+ * Откат правок сетки к состоянию, по которому идёт эфир: восстанавливает слои, слоты и правила
+ * из снимка последнего применения. Ленту не трогает — она и так по этому состоянию.
+ */
+export function restoreChannelTemplate(channelId: string) {
+  return apiRequest<RestoreTemplateResultDto>(`/admin/channels/${channelId}/template/restore`, {
+    method: 'POST',
+  })
+}
+
 /** Проверки сетки по правилам — считаются по шаблону, без прогона генератора. */
 export function getTemplateIssues(channelId: string) {
   return apiRequest<TemplateIssueDto[]>(`/admin/channels/${channelId}/template/issues`)