Settings rows carried their own platform-conditional typography and
density, so on desktop and TV they rendered a 16px title, 14px subtitle
and 80px row while every other row in the app — the Focusable*ListTile
defaults plus ThemeData.listTileTheme's `dense: true` — renders 13/12
in 61px.
Drop the overrides instead of re-tuning them: the tile defaults already
encode the app's row style, and the explicit title styles were redundant
under a dense ListTile (they also masked the disabled/selected title
color). settingsOptionTitleStyle now only serves group children that are
not ListTiles, and matches the dense title unconditionally.
SettingsGroup hands its children that same compact density, so the plain
ListTiles used as non-interactive info rows stop standing 11px taller
than their interactive siblings.
Introduces shared seams for paginated views, D-pad reorder, media control
routing, async singletons and the device method channel, then points the
open-coded copies at them.
Also removes unused models and duplicated provider/server plumbing, folds
the twice-implemented artifact store in the server, and factors the
repeated Flutter toolchain prologue in CI into a composite action.
edde746