feat: Intégration du backend NestJS depuis YNOV

- Framework: NestJS avec TypeORM
- Authentification: JWT (access + refresh tokens)
- Gestion utilisateurs: CRUD complet avec validation
- Routes: auth, users, parents, assistantes maternelles
- Dockerfile pour conteneurisation

backend/src/routes/enfants/dto/enfants_response.dto.ts

@@ -0,0 +1,37 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { GenreType, StatutEnfantType } from 'src/entities/children.entity';
+
+export class EnfantResponseDto {
+  @ApiProperty({ example: 'UUID-enfant' })
+  id: string;
+
+  @ApiProperty({ enum: StatutEnfantType })
+  status: StatutEnfantType;
+
+  @ApiProperty({ example: 'Georges', required: false })
+  first_name?: string;
+
+  @ApiProperty({ example: 'Dupont', required: false })
+  last_name?: string;
+
+  @ApiProperty({ enum: GenreType, required: false })
+  gender?: GenreType;
+
+  @ApiProperty({ example: '2018-06-24', required: false })
+  birth_date?: string;
+
+  @ApiProperty({ example: '2025-12-15', required: false })
+  due_date?: string;
+
+  @ApiProperty({ example: 'https://monimage.com/photo.jpg', required: false })
+  photo_url?: string;
+
+  @ApiProperty({ example: false })
+  consent_photo: boolean;
+
+  @ApiProperty({ example: false })
+  is_multiple: boolean;
+
+  @ApiProperty({ example: 'UUID-parent' })
+  parent_id: string;
+}