Safer global button styles

Removed a global reset that could affect buttons outside the design system.

Fixed

Removed the global button { all: unset; } reset. Native buttons and buttons from other libraries no longer lose their default styles simply because Vortex styles are loaded.

Vortex button styles are now scoped to Vortex components instead of changing the behavior of every button element on the page. This makes incremental adoption safer: teams can load the design-system stylesheet while keeping existing product and third-party controls intact.