Collapse the today icon-button block that was copy-pasted into all four
calendar top bars (Week/Month/Day/Agenda) into one TodayAction composable in
ui/common. No behaviour change.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add a "Today button in toolbar" appearance toggle (default off). When on,
each calendar view (month/week/day/agenda) shows a persistent go-to-today
icon button in its top bar instead of the fade-in extended FAB, and the
FAB pill is suppressed. Same jump action, just always present.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>