feat: hotel radio widget (client-side, multi-station)

Adds a compact collapsible radio widget (top-left) that plays internet
radio streams with the HTML5 Audio API — no server/renderer changes.

- station list loaded from a JSON5 config file (loadGamedata: JSON + JSON5),
  shipped as radio-stations.json5.example so each hotel fills in its own
- shows the selected station + a dropdown (3 visible, scrolls if more) to
  switch; volume slider; animated equalizer + LIVE indicator
- first station autostarts quietly (5%) on load, with a resume-on-first-
  gesture fallback for browser autoplay policy

src/hooks/index.ts

@@ -15,6 +15,7 @@ export * from './mod-tools';
 export * from './navigator';
 export * from './notification';
 export * from './purse';
+export * from './radio/useRadio';
 export * from './rare-values/useRareValues';
 export * from './rooms';
 export * from './rooms/engine';