feat(contents): add updateAdmin endpoint and repository method

- Introduced `PATCH /:id/admin` endpoint to update admin-specific content.
- Added `update` method to `ContentsRepository` for data updates with timestamp.

backend/src/contents/contents.controller.ts

@@ -10,6 +10,7 @@ import {
 	Param,
 	ParseBoolPipe,
 	ParseIntPipe,
+	Patch,
 	Post,
 	Query,
 	Req,
@@ -185,4 +186,11 @@ export class ContentsController {
 	removeAdmin(@Param("id") id: string) {
 		return this.contentsService.removeAdmin(id);
 	}
+
+	@Patch(":id/admin")
+	@UseGuards(AuthGuard, RolesGuard)
+	@Roles("admin")
+	updateAdmin(@Param("id") id: string, @Body() updateContentDto: any) {
+		return this.contentsService.updateAdmin(id, updateContentDto);
+	}
 }