fix: block deactivating an apiary while it still has active colonies

Colony.apiaryId is a plain FK, never checked against the apiary's own
status. Without a guard, deactivating an apiary silently orphaned any
colonies still living there: they kept showing as ACTIVE, but their
apiary had disappeared from every "active apiaries" list, dashboard
count, and colony-creation picker - a confusing half-state with no
warning at all.

ApiariesService.deactivate() now throws ConflictException when active
colonies remain, so the beekeeper has to move or dissolve them first -
matching the same assertActive-style guard pattern already used
elsewhere (colonies, e.g. move()/merge()/split()).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ApiCore-Backend/src/apiaries/apiaries.service.spec.ts

@@ -12,6 +12,7 @@ describe('ApiariesService', () => {
       create: jest.Mock;
       update: jest.Mock;
     };
+    colony: { count: jest.Mock };
   };
   let auditLog: { record: jest.Mock };
 
@@ -30,6 +31,7 @@ describe('ApiariesService', () => {
         create: jest.fn(),
         update: jest.fn(),
       },
+      colony: { count: jest.fn().mockResolvedValue(0) },
     };
     auditLog = { record: jest.fn().mockResolvedValue(undefined) };
     service = new ApiariesService(
@@ -76,6 +78,16 @@ describe('ApiariesService', () => {
     );
   });
 
+  it('deactivate throws ConflictException when active colonies remain', async () => {
+    prisma.apiary.findUnique.mockResolvedValue(existingApiary);
+    prisma.colony.count.mockResolvedValue(2);
+
+    await expect(
+      service.deactivate('apiary-1', 'user-1'),
+    ).rejects.toBeInstanceOf(ConflictException);
+    expect(prisma.apiary.update).not.toHaveBeenCalled();
+  });
+
   it('reactivate throws ConflictException when already active', async () => {
     prisma.apiary.findUnique.mockResolvedValue(existingApiary);
     await expect(