chore: upgrade TypeScript 4.9 to 5.9, ESLint 8.29 to 8.57, @typescript-eslint 5 to 7

Resolves all TS2345/TS2347/TS7006 type errors introduced by stricter TypeScript 5.x.
Fix Icons.Settings to Icons.Setting, cast account data returns, fix implicit any.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/components/CallEmbedProvider.tsx

@@ -467,7 +467,7 @@ export function CallEmbedProvider({ children }: CallEmbedProviderProps) {
       });
       el.style.visibility = callVisible ? '' : 'hidden';
     }
-    prevPipModeRef.current = pipMode;
+    prevPipModeRef.current = !!pipMode;
   }, [pipMode, callVisible]);
 
   React.useEffect(() => {