Sync LMS backend source

src/chat/dto/create-ai-response.dto.ts

@@ -0,0 +1,12 @@
+import { IsInt, IsOptional, IsString, Max, Min } from 'class-validator';
+
+export class CreateAiResponseDto {
+  @IsString()
+  content: string;
+
+  @IsOptional()
+  @IsInt()
+  @Min(1)
+  @Max(100)
+  week?: number;
+}