fix: add missing authHeader: true to Longcat provider preset (#1377)

Fixes issue where Longcat models were failing with 404 error due to missing
authHeader configuration. According to Longcat API documentation, this
setting is required for proper authentication.

Closes: #1376

src/config/openclawProviderPresets.ts

@@ -458,6 +458,7 @@ export const openclawProviderPresets: OpenClawProviderPreset[] = [
       baseUrl: "https://api.longcat.chat/v1",
       apiKey: "",
       api: "openai-completions",
+      authHeader: true,
       models: [
         {
           id: "LongCat-Flash-Chat",