Restore nest coverage to >=80% after the #1209 dep bump (istanbul provider + branch tests) (#1213)

* fix(server): set oxc:false in vitest so the SWC transform survives the Vite 8 bump

* fix(server): switch coverage to the istanbul provider (v8 under-reports branches on Vite 8 + Vitest 4)

* test(nest): cover controller/service branches to clear the 80% coverage gate

server/tests/unit/nest/trips.service.test.ts

@@ -53,6 +53,12 @@ describe('TripsService (wrapper delegation + bundle/copy/notify helpers)', () =>
     s.exportICS('9'); expect(tripSvc.exportICS).toHaveBeenCalledWith('9');
   });
 
+  it('canAccessTrip delegates to the db helper', () => {
+    canAccessTrip.mockReturnValueOnce({ user_id: 7 });
+    expect(svc().canAccessTrip('9', 7)).toEqual({ user_id: 7 });
+    expect(canAccessTrip).toHaveBeenCalledWith('9', 7);
+  });
+
   it('can() delegates to checkPermission; broadcast forwards', () => {
     svc().can('trip_edit', 'user', 1, 1, false);
     expect(checkPermission).toHaveBeenCalledWith('trip_edit', 'user', 1, 1, false);
@@ -70,6 +76,12 @@ describe('TripsService (wrapper delegation + bundle/copy/notify helpers)', () =>
     expect(result).toMatchObject({ trip: { user_id: 1 }, days: [1], places: [], members: [{ id: 1 }] });
   });
 
+  it('bundle tolerates a null member list', () => {
+    tripSvc.listMembers.mockReturnValueOnce({ owner: { id: 1 }, members: null });
+    const result = svc().bundle('9', { user_id: 1 });
+    expect(result).toMatchObject({ members: [{ id: 1 }] });
+  });
+
   it('notifyInvite is fire-and-forget (no throw)', () => {
     expect(() => svc().notifyInvite('9', { id: 1, email: 'a@b.c' } as never, 2, 'T', 'b@x.y')).not.toThrow();
   });