Introduces MonthViewStyle{Paged, Continuous, Split} and the setting that
chooses it. Only Paged is wired up so far — the other two land next; this
commit is the pref, the state plumbing and the chooser.
One picker rather than two switches ("vertical scrolling" + "month with
agenda"): independent toggles would multiply into four combinations, most of
which nobody asked for. Split does not disable the Agenda view — that stays a
forward multi-day window, while the split pane lists one selected day.
The chooser lives on the Views settings screen (per-view layout belongs with
the other view configuration) and is a hand-rolled FullScreenPicker rather than
OptionPicker, which cannot render previews: the three options differ in shape,
which a word like "Continuous" does not convey. Each card carries a schematic
drawn from theme tokens, and selection reads three ways over — border weight,
container tint and a check — so it never rests on colour alone. The cards are a
selectableGroup with Role.RadioButton for screen readers.
Folded into the ViewCustomization holder, which had spare arity; the outer
settings combine is still at its five-flow limit.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jean-Luc Makiola
7510e1f9af