The right-sidebar terminal hardcoded a light palette, which read poorly
on the dark glass surface. Subscribe to `useTheme().resolvedMode` and
hot-swap `term.options.theme` so Shift+X (and any other mode change)
updates the terminal in place without tearing down the PTY session.
Dark mode uses xterm's built-in defaults (white fg/cursor + vivid ANSI
16) with just a transparent background so the glass shows through;
light mode keeps the existing hand-tuned overrides for legibility on a
bright surface.
Brooklyn Nicholson
eb68d66ff9