zen: fix aws bedrock header

packages/console/app/src/routes/zen/util/provider/anthropic.ts

@@ -43,7 +43,7 @@ export const anthropicHelper: ProviderHelper = ({ reqModel, providerModel }) =>
       ...(isBedrock
         ? {
             anthropic_version: "bedrock-2023-05-31",
-            anthropic_beta: supports1m ? "context-1m-2025-08-07" : undefined,
+            anthropic_beta: supports1m ? ["context-1m-2025-08-07"] : undefined,
             model: undefined,
             stream: undefined,
           }