feat(rbac): add RbacController with role CRUD, permissions tree, and user management endpoints

backend/src/rbac/dto/rbac.dto.ts

@@ -0,0 +1,68 @@
+import { IsString, MinLength, IsOptional, IsArray, IsBoolean } from 'class-validator';
+
+export class CreateRoleDto {
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsString()
+  description?: string;
+
+  @IsOptional()
+  @IsArray()
+  permissionIds?: number[];
+}
+
+export class UpdateRoleDto {
+  @IsOptional()
+  @IsString()
+  name?: string;
+
+  @IsOptional()
+  @IsString()
+  description?: string;
+
+  @IsOptional()
+  @IsArray()
+  permissionIds?: number[];
+}
+
+export class CreateUserDto {
+  @IsString()
+  username: string;
+
+  @IsString()
+  @MinLength(4)
+  password: string;
+
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsArray()
+  roleIds?: number[];
+}
+
+export class UpdateUserDto {
+  @IsOptional()
+  @IsString()
+  username?: string;
+
+  @IsOptional()
+  @IsString()
+  name?: string;
+
+  @IsOptional()
+  @IsBoolean()
+  isActive?: boolean;
+
+  @IsOptional()
+  @IsArray()
+  roleIds?: number[];
+}
+
+export class ResetPasswordDto {
+  @IsString()
+  @MinLength(4)
+  password: string;
+}