Add blog post admin CRUD API.

Expose JWT-protected /blog-posts endpoints for draft creation, listing, update, and delete.

backend/src/modules/blog/dto/UpdateBlogPostDto.ts

@@ -0,0 +1,21 @@
+import { IsBoolean, IsNotEmpty, IsString, MaxLength } from 'class-validator';
+
+import { getAppConfig } from '../../../config';
+
+const {
+    validation: { blogPostTitleMaxLength }
+} = getAppConfig();
+
+export class UpdateBlogPostDto {
+    @IsNotEmpty()
+    @IsString()
+    @MaxLength(blogPostTitleMaxLength)
+    title: string;
+
+    @IsString()
+    contentHtml: string;
+
+    @IsNotEmpty()
+    @IsBoolean()
+    isDraft: boolean;
+}