Reachable from a gear icon on every tab, composed from kit components
(GroupedRow/OptionPicker/AboutCard/LanguagePickerRow) following
Calendula's hub shape: About card first, then headed groups. Every
control writes immediately — no Save button, same as the alarm editor.
Appearance: theme, dynamic colour (API 31+), language. Alarm and timer
defaults reuse the editor's own ringtone and override pickers
(OverridePickers gets an includeAppDefault flag so the settings rows
don't offer an 'inherit' option that has nothing above it to inherit
from) and the world clock's home-zone picker. Reliability and Data
rows are placeholders for the self-check and backup screens landing
next. Help surfaces the issue tracker, a pending crash report (the
same dialog MainActivity already shows on launch), and the app
version.
Settings has no owning tab — ShellNavigation.selectedDestinationOf
deliberately leaves it unmapped, so the shell falls back to Alarms
while it's open, same as any other unrecognised route.