基岩: 拒绝具有非对象 JSON 输出的工具结果(工具结果.content[].json 必须是对象)

Describe the bug With the bedrock client, any tool whose output is a top-level JSON array (or string/number/null) makes the follow-up request fail. Bedrock's Converse API requires the value under toolResult.content[].json to be a JSON object, but aichat always places the raw tool output there. This breaks MCP/function-calling tools that don't return an object. The same tools work on the Anthropic-native client.