feat(#159): suppressions métier dossiers/parents/enfants/AM/staff.

SuppressionService + DELETE /dossiers/:numero, cascades DELETE /users et
DELETE /enfants?deleteDossier, flag sans_enfant, specs front #160.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/routes/dossiers/dossiers.controller.spec.ts

@@ -1,6 +1,7 @@
 import { Test, TestingModule } from '@nestjs/testing';
 import { DossiersController } from './dossiers.controller';
 import { DossiersService } from './dossiers.service';
+import { SuppressionService } from '../suppressions/suppression.service';
 import { AuthGuard } from 'src/common/guards/auth.guard';
 import { RolesGuard } from 'src/common/guards/roles.guard';
 import { StatutUtilisateurType } from 'src/entities/users.entity';
@@ -11,11 +12,17 @@ describe('DossiersController', () => {
     listDossiers: jest.fn(),
     getDossierByNumero: jest.fn(),
   };
+  const suppressionServiceMock = {
+    deleteDossier: jest.fn(),
+  };
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
       controllers: [DossiersController],
-      providers: [{ provide: DossiersService, useValue: dossiersServiceMock }],
+      providers: [
+        { provide: DossiersService, useValue: dossiersServiceMock },
+        { provide: SuppressionService, useValue: suppressionServiceMock },
+      ],
     })
       .overrideGuard(AuthGuard)
       .useValue({ canActivate: () => true })
@@ -60,4 +67,19 @@ describe('DossiersController', () => {
     expect(dossiersServiceMock.getDossierByNumero).toHaveBeenCalledWith('2026-000001');
     expect(res.type).toBe('family');
   });
+
+  it('remove delegates to suppressionService.deleteDossier', async () => {
+    const user = { id: 'u1', role: 'gestionnaire' } as never;
+    suppressionServiceMock.deleteDossier.mockResolvedValue({
+      type: 'famille',
+      deleted_user_ids: [],
+      deleted_enfant_ids: [],
+      message: 'ok',
+    });
+    await controller.remove('2026-000001', user);
+    expect(suppressionServiceMock.deleteDossier).toHaveBeenCalledWith(
+      '2026-000001',
+      user,
+    );
+  });
 });