i18n(ar): mirror the layout right to left

- The title, style indicator and both rails swap sides in RTL through logical
  properties (inset-inline-*, margin-inline-*, border-inline-start); LTR
  computes the same values. The Display/Context rail keeps its physical
  `right` for the credit-clearance model and swaps in rtl.css above 720px.
- rtl.css: no letter-spacing on Arabic (it tears joined letters apart);
  Noto Sans Arabic leads the Arabic font stacks so words are not set in a
  fixed-pitch fallback; the intel HUD and cockpit instruments stay a
  left-to-right instrument overlay; media transport and the radio dial stay
  left to right; feed headlines and station names take their own direction;
  the moved rail's arrows flip.
- isolate(): a quantity in RTL text (2.7 كم, -18.0°) is wrapped in
  first-strong isolates so its digits do not join a neighbouring Latin run.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

style.css

@@ -33,5 +33,6 @@
 @import './src/ui/styles/panel-surfaces.css';
 @import './src/ui/styles/segmented-control.css';
 @import './src/ui/styles/cjk.css';
+@import './src/ui/styles/rtl.css';
 @import './src/ui/styles/mobile-shell.css';
 @import './src/ui/styles/cyber.css';