feat(users, contents): extend admin update functionality and role management

- Added `moderator` role to `User` type for improved role assignment flexibility.
- Introduced `updateAdmin` method in user and content services to handle partial admin-specific updates.
- Enhanced `Content` type with `categoryId` and `iconUrl` to support richer categorization.

frontend/src/types/content.ts

@@ -18,6 +18,7 @@ export interface Content {
 	favoritesCount: number;
 	isLiked?: boolean;
 	tags: (string | Tag)[];
+	categoryId?: string | null;
 	category?: Category;
 	authorId: string;
 	author: User;
@@ -36,6 +37,7 @@ export interface Category {
 	name: string;
 	slug: string;
 	description?: string;
+	iconUrl?: string;
 }
 
 export interface PaginatedResponse<T> {

frontend/src/types/user.ts

@@ -6,7 +6,7 @@ export interface User {
 	displayName?: string;
 	avatarUrl?: string;
 	bio?: string;
-	role?: "user" | "admin";
+	role?: "user" | "admin" | "moderator";
 	status?: "active" | "verification" | "suspended" | "pending" | "deleted";
 	createdAt: string;
 }