Describe the bug

When HarnessAgent enables subagent orchestration, the task_output tool supports blocking up to 10 minutes via its timeout parameter. However, the default tool execution configuration (ExecutionConfig.TOOL_DEFAULTS) times out after 5 minutes.

As a result, a long-running task_output(block=true, timeout=600000) call may be interrupted by the framework-level tool timeout before the task output wait reaches its own maximum timeout.

To Reproduce

1. Create a HarnessAgent with subagents enabled and no custom toolExecutionConfig.
2. Spawn a background subagent task that takes longer than 5 minutes but less than 10 minutes.
3. Call task_output with block=true and timeout=600000.
4. Observe that the tool execution may fail after about 5 minutes.

Example error:

Tool execution failed: Tool execution timeout after PT5M