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/components/MainView.tsx

@@ -27,6 +27,7 @@ import { HousekeepingView } from './housekeeping/HousekeepingView';
 import { RareValuesView } from './rare-values/RareValuesView';
 import { FortuneWheelView } from './fortune-wheel/FortuneWheelView';
 import { SoundboardView } from './soundboard/SoundboardView';
+import { RadioView } from './radio/RadioView';
 import { InventoryView } from './inventory/InventoryView';
 import { ModToolsView } from './mod-tools/ModToolsView';
 import { NavigatorView } from './navigator/NavigatorView';
@@ -182,6 +183,7 @@ export const MainView: FC<{}> = props =>
             <RareValuesView />
             <FortuneWheelView />
             <SoundboardView />
+            <RadioView />
             <ExternalPluginLoader />
         </>
     );