Fixes a bug where the popup could not be scrolled when its contents ran past the visible area, leaving the lower part of the shortcuts list and the settings pane unreachable. Also removes a small unwanted gap along the right edge of the settings pane.

Source: TypeScript bundled with esbuild, no minification (build sets minify:false). To reproduce the uploaded dist/firefox package: install Node 20+, run npm install, then node scripts/build.mjs firefox. The output in dist/firefox/ matches this package byte-for-byte except timestamps. Full source archive available on request.