Migrate the user-facing strings in builtin.git (panel, status groups, commit
bar, branch picker, discard dialog, row a11y) and builtin.diff (toolbar,
empty states, file meta) to ClideSettings.i18n.string/.interpolated; extend
both catalogs. _stateLabel threaded a BuildContext from its caller. No en_US
behaviour change (D-21).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>