Structural:
- Merge factory + singleton from lib/settingsManager and model/state into
one model/store/typographySettingsStore/ slice
- Drop now-empty lib/ and model/state/ directories
Semantic:
- Rename feature SetupFont -> AdjustTypography (the feature owns
continuous typography adjustment, not one-time font setup)
- Drop "Manager" from TypographySettingsManager -> TypographySettingsStore
(class + factory); singleton typographySettingsStore unchanged
All consumers (Character, Line, SampleList, SliderArea, FontSampler,
comparisonStore) updated. Public barrel signature changed: now exports
createTypographySettingsStore and type TypographySettingsStore.
Ilia Mashkov