fix: 增强错误解析以支持中转服务的嵌套错误结构

src/actions/providers.ts

@@ -1057,6 +1057,30 @@ function extractErrorMessage(errorJson: unknown): string | undefined {
     return undefined;
   }
 
+  const obj = errorJson as Record<string, unknown>;
+
+  // 优先提取 upstream_error 中的错误信息（针对中转服务的嵌套错误）
+  const upstreamError = (obj.error as { upstream_error?: unknown } | undefined)?.upstream_error;
+
+  if (upstreamError && typeof upstreamError === "object") {
+    const upstreamErrorObj = upstreamError as Record<string, unknown>;
+
+    // 尝试从 upstream_error.error.message 提取
+    const nestedMessage = normalizeErrorValue(
+      (upstreamErrorObj.error as { message?: unknown } | undefined)?.message
+    );
+    if (nestedMessage) {
+      return nestedMessage;
+    }
+
+    // 尝试从 upstream_error.message 提取
+    const directMessage = normalizeErrorValue(upstreamErrorObj.message);
+    if (directMessage) {
+      return directMessage;
+    }
+  }
+
+  // 常规错误提取逻辑（保持原有优先级）
   const candidates: Array<(obj: Record<string, unknown>) => unknown> = [
     (obj) => (obj.error as Record<string, unknown> | undefined)?.message,
     (obj) => obj.message,
@@ -1069,7 +1093,7 @@ function extractErrorMessage(errorJson: unknown): string | undefined {
   for (const getter of candidates) {
     let value: unknown;
     try {
-      value = getter(errorJson as Record<string, unknown>);
+      value = getter(obj);
     } catch {
       continue;
     }