- Set active=false for newly registered users
- Return RegistrationResponse instead of SessionResponse after registration
- Show success message informing user that admin approval is pending
- Login check already filters for active users only
- Add nextSampleNumber field to AppUser record with default 100000
- Add compact constructor to initialize nextSampleNumber to 100000
- Add reserveNextSampleNumber method to atomically reserve and increment
- Update createSample to use reserveNextSampleNumber from user
- Update nextSampleNumber to read from user collection
- Update dashboardOverview to use new nextSampleNumber method
- Add findTopByOwnerAccountIdOrderBySampleNumberDesc to SampleRepository
- Modify nextSampleNumber to accept ownerAccountId parameter
- Calculate next sample number per user based on ownerAccountId
- Update dashboardOverview and createSample to use user-specific numbering
