Dialogs are separate WPF windows, so the FontFamily set on MainWindow never reached them —
GoLive, Socials and the four pickers still rendered Segoe UI while the main window used Inter.
The theme now carries an implicit Window style (family + Display text mode + layout rounding).
Guard: DialogTypographyTests opens a real Window inside the real app and asserts it resolves the
bundled Inter family — which fails if the style or the font resource goes missing — and asserts
no dialog sets FontFamily itself, i.e. nobody opts out of the standard.
