Inject Clock into CalendarViewModel for testability, add kotlinx-coroutines-test dependency, replace placeholder test with real coverage for ISO week numbers, month day grids, page mapping, and utility functions.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
When swiping to a different month or week, select today if it falls
within the target period instead of always picking the 1st or Monday.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
