Code-review follow-up. AppTopbar DarkTheme mutated <html>.dark which
leaked into Default/CompactDensity stacked on the same autodocs page;
scope dark to the story subtree via a `.dark` wrapper (Aura
darkModeSelector is the `.dark` class) — verified isolated on the docs
page. Also factor the duplicated render scaffolds in AppDialog (shared
dialogStory factory) and WorkspaceSwitcher (meta-level render).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
bert.hausmans
92d8051903