feat(document): EntityDocumentsService + autoTitle + soft-delete cascade

list/create/delete for Document attached to ClientContract, DeliveryLot,
ClientInvoice. Auto-titles from entity fields. Soft-delete cascades to
DocumentFile.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/modules/documents/entity-documents.service.ts

@@ -0,0 +1,109 @@
+import { PrismaClient, DocumentType, DocumentDirection, Prisma } from '@prisma/client';
+
+export type EntityKind = 'client-contract' | 'delivery-lot' | 'client-invoice';
+
+interface CreateDto {
+  documentType: DocumentType;
+  title?: string;
+  direction?: DocumentDirection;
+  parentDocumentId?: number;
+  responsibleId?: string;
+}
+
+const FK_MAP: Record<EntityKind, string> = {
+  'client-contract': 'clientContractId',
+  'delivery-lot': 'deliveryLotId',
+  'client-invoice': 'clientInvoiceId',
+};
+
+const DEFAULT_DIRECTION: Record<EntityKind, DocumentDirection> = {
+  'client-contract': 'CLIENT',
+  'delivery-lot': 'SUPPLIER',
+  'client-invoice': 'CLIENT',
+};
+
+const DOCUMENT_INCLUDE = {
+  responsible: { select: { id: true, name: true, nameRu: true } },
+  files: { where: { deletedAt: null }, select: { id: true, originalName: true, version: true, isLatest: true, mimeType: true, fileSize: true, createdAt: true } },
+} as const;
+
+export function autoTitleForEntity(kind: EntityKind, entity: any): string {
+  switch (kind) {
+    case 'client-contract': return `Контракт ${entity.contractNumber ?? ''}`.trim();
+    case 'delivery-lot': return `УПД ${entity.updNumber ?? ''}`.trim();
+    case 'client-invoice': return `Счёт ${entity.invoiceNumber ?? ''}`.trim();
+  }
+}
+
+export class EntityDocumentsService {
+  constructor(private prisma: PrismaClient) {}
+
+  async list(kind: EntityKind, entityId: number) {
+    const fk = FK_MAP[kind];
+    return this.prisma.document.findMany({
+      where: { [fk]: entityId, deletedAt: null },
+      include: DOCUMENT_INCLUDE,
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+
+  async create(kind: EntityKind, entityId: number, dto: CreateDto, userId?: string) {
+    const entity = await this.loadEntity(kind, entityId);
+    if (!entity) {
+      const err = new Error('Entité non trouvée') as any;
+      err.statusCode = 404;
+      throw err;
+    }
+
+    if (dto.parentDocumentId) {
+      const parent = await this.prisma.document.findFirst({
+        where: { id: dto.parentDocumentId, [FK_MAP[kind]]: entityId, deletedAt: null },
+      });
+      if (!parent) {
+        const err = new Error('Document parent introuvable ou appartient à une autre entité') as any;
+        err.statusCode = 400;
+        throw err;
+      }
+    }
+
+    const title = dto.title || autoTitleForEntity(kind, entity);
+    const direction = dto.direction ?? DEFAULT_DIRECTION[kind];
+
+    return this.prisma.document.create({
+      data: {
+        documentType: dto.documentType,
+        title,
+        direction,
+        [FK_MAP[kind]]: entityId,
+        responsibleId: dto.responsibleId ?? userId,
+        parentDocumentId: dto.parentDocumentId,
+      },
+      include: DOCUMENT_INCLUDE,
+    });
+  }
+
+  async delete(documentId: number) {
+    const now = new Date();
+    await this.prisma.$transaction([
+      this.prisma.document.update({
+        where: { id: documentId },
+        data: { deletedAt: now },
+      }),
+      this.prisma.documentFile.updateMany({
+        where: { documentId, deletedAt: null },
+        data: { deletedAt: now },
+      }),
+    ]);
+  }
+
+  private async loadEntity(kind: EntityKind, entityId: number) {
+    switch (kind) {
+      case 'client-contract':
+        return this.prisma.clientContract.findUnique({ where: { id: entityId } });
+      case 'delivery-lot':
+        return this.prisma.deliveryLot.findUnique({ where: { id: entityId } });
+      case 'client-invoice':
+        return this.prisma.clientInvoice.findUnique({ where: { id: entityId } });
+    }
+  }
+}