feat(api): add reviews module with CRUD endpoints and CQRS

Implement polymorphic reviews system supporting any target type (agent,
property, etc.) with DDD/CQRS architecture following existing patterns.

Endpoints:
- POST /api/reviews — create review (authenticated)
- GET /api/reviews?targetType=&targetId= — list reviews by target
- GET /api/reviews/stats?targetType=&targetId= — aggregate rating stats
- GET /api/reviews/me — list authenticated user's reviews
- DELETE /api/reviews/:id — delete own review

Business rules: 1-5 rating validation, self-review prevention, one
review per user per target. Includes 15 unit tests for all handlers.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/reviews/presentation/dto/create-review.dto.ts

@@ -0,0 +1,26 @@
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+import { IsInt, IsNotEmpty, IsOptional, IsString, Max, MaxLength, Min } from 'class-validator';
+
+export class CreateReviewDto {
+  @ApiProperty({ example: 'agent', description: 'Target entity type (e.g. agent, property)' })
+  @IsString()
+  @IsNotEmpty()
+  targetType!: string;
+
+  @ApiProperty({ example: 'clxyz123', description: 'Target entity ID' })
+  @IsString()
+  @IsNotEmpty()
+  targetId!: string;
+
+  @ApiProperty({ example: 5, description: 'Rating from 1 to 5', minimum: 1, maximum: 5 })
+  @IsInt()
+  @Min(1)
+  @Max(5)
+  rating!: number;
+
+  @ApiPropertyOptional({ example: 'Dịch vụ rất tốt!', description: 'Optional review comment' })
+  @IsOptional()
+  @IsString()
+  @MaxLength(2000)
+  comment?: string;
+}