Implement the full Settings tab with household size and daily kcal/person
input fields, persisted via Room through the existing SettingsRepository.
The DashboardViewModel now reads settings reactively and passes them to
CalculateSupplyRangeUseCase instead of using hardcoded defaults.
Changes:
- Add observeValue(key) Flow method to SettingsDao and SettingsRepository
- Create SettingsViewModel with load/save logic and input validation
- Create SettingsUiState data class
- Replace SettingsScreen placeholder with full Compose UI
(household size, kcal/day fields, save button, export/import placeholders)
- Integrate settings into DashboardViewModel via combine() with 4 flows
- Add SettingsViewModelTest (6 tests covering defaults, persistence, validation)
- Update DashboardViewModelTest and test fakes for new constructor parameter
Closes#35
e85b151cd5