fix(platform): recognize session faults across realms

cocoscreator_projects/YouleNexus/assets/framework/sdk/runtime/game-session-host.ts

@@ -7,6 +7,9 @@ import type {
 } from '../contracts/index.ts';
 
 const RESERVED_ROUTES = new Set(['platform', 'agent', 'room']);
+const GAME_SESSION_OPEN_FAULT_BRAND = Symbol.for(
+  'youle.framework.sdk.GameSessionOpenFault',
+);
 
 export type GameSessionState =
   | 'idle'
@@ -22,10 +25,33 @@ export class GameSessionOpenFault extends Error {
   constructor(primary: unknown, cleanup: unknown) {
     super('Game session open failed and module cleanup also failed');
     this.name = 'GameSessionOpenFault';
+    Object.defineProperty(this, GAME_SESSION_OPEN_FAULT_BRAND, { value: true });
     this.errors = Object.freeze([primary, cleanup]);
   }
 }
 
+export interface GameSessionOpenFaultShape {
+  readonly errors: readonly [unknown, unknown];
+}
+
+/** Recognizes open faults across realms and duplicate module instances. */
+export function isGameSessionOpenFault(value: unknown): value is GameSessionOpenFaultShape {
+  if (value === null || typeof value !== 'object') return false;
+
+  try {
+    const brand = ownDataDescriptor(value, GAME_SESSION_OPEN_FAULT_BRAND);
+    const errors = ownDataDescriptor(value, 'errors');
+    if (brand?.value !== true || !errors || !Array.isArray(errors.value)) return false;
+
+    const errorList = errors.value;
+    return ownDataDescriptor(errorList, 'length')?.value === 2
+      && ownDataDescriptor(errorList, '0') !== undefined
+      && ownDataDescriptor(errorList, '1') !== undefined;
+  } catch {
+    return false;
+  }
+}
+
 /** Validates the compile-time game identity before it reaches the runtime. */
 export function assertGameEntry(entry: GameEntry): void {
   assertNonEmptyText(entry.key, 'key');
@@ -195,3 +221,10 @@ function disposeModuleIfPresent(module: unknown): void {
   const dispose = (module as Record<string, unknown>).dispose;
   if (typeof dispose === 'function') dispose.call(module);
 }
+
+function ownDataDescriptor(target: object, key: PropertyKey): PropertyDescriptor | undefined {
+  const descriptor = Object.getOwnPropertyDescriptor(target, key);
+  return descriptor && Object.prototype.hasOwnProperty.call(descriptor, 'value')
+    ? descriptor
+    : undefined;
+}