fix(auth): isolate client cache by session

vehicle-data-platform/apps/web/src/v2/auth/session.ts

@@ -1,4 +1,5 @@
 const TOKEN_KEY = 'vehicle-platform.access-token';
+export const PLATFORM_UNAUTHORIZED_EVENT = 'vehicle-platform:unauthorized';
 
 export type PlatformRole = 'viewer' | 'operator' | 'admin';
 
@@ -22,6 +23,10 @@ export function clearAccessToken() {
   window.sessionStorage.removeItem(TOKEN_KEY);
 }
 
+export function notifyUnauthorizedSession() {
+  window.dispatchEvent(new Event(PLATFORM_UNAUTHORIZED_EVENT));
+}
+
 export function canOperate(session: PlatformSession) {
   return session.role === 'operator' || session.role === 'admin';
 }