fix(HEL-494): 修复个股缺失指标、问天遮罩、四爻外显并回补250日K

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

frontend/shared/api.js

@@ -62,6 +62,9 @@
     try {
       response = await fetch(url, requestOptions(method, body, options.signal));
     } catch (error) {
+      if (error?.name === "AbortError") {
+        throw new ApiError("请求已取消或超时", 0, { aborted: true });
+      }
       throw new ApiError(readableRequestError(error), 0, null);
     }
     const payload = await parseJson(response);