feat(ui): apply Tokyo Night Storm theme with semantic CSS tokens

feat(ui): apply Tokyo Night Storm theme with semantic CSS tokens

Add theme.css with two-layer token system: primitive tokens from
the official Tokyo Night Storm palette, semantic tokens mapping UI
roles to primitives. All components use semantic tokens exclusively.

Replace all hardcoded colors across 13 Vue components. Theme native
HTML elements (button, input, select, a, headings) globally. Toggle
button pressed state uses palette-semantic active bg + accent border
+ inset shadow for clear visual distinction.

Remove dead code: simulatorButtonClass computed and associated CSS
classes that duplicated global button styles.