错误上报取文案改if-else链

- errorReporting 的嵌套三元改为 if/else 赋值，行为不变，只提高可读性

apps/ai-game-creator-shell/src/services/errorReporting.ts

@@ -85,12 +85,14 @@ export async function captureClientError(
   const actionError = error instanceof ClientAuthErrorWrapper ? error : null;
   // 类型上 `error` 是 ClientAuthError；Tauri 在映射外抛 Error 属于它的缺陷，这里按 unknown 兜底取文案/栈。
   const carried: unknown = actionError?.error;
-  const errorValue =
-    carried instanceof Error
-      ? carried
-      : error instanceof Error
-        ? error
-        : new Error(String(error));
+  let errorValue: Error;
+  if (carried instanceof Error) {
+    errorValue = carried;
+  } else if (error instanceof Error) {
+    errorValue = error;
+  } else {
+    errorValue = new Error(String(error));
+  }
   const message = errorValue.message || '未知客户端错误';
   const stack = errorValue.stack?.slice(0, 8_000);
   return reportClientError({