fix(agents): subgraphWithTask & subtask missing tool results in prompt if other tools where requested along with finish tool

[EugeneTheDev]

In subgraphWithTask models can sometimes request other tools along with the finish tool. Previously, other tool results were ignored and not added to prompt, which led to error, since prompts can't have tool calls without matching tool results. Updated the subgraphWithTask logic to append all tool results when the finish tool was called

[Amaneusz]

I think removing this might need more attention

• executeFinishTool is called from AIAgentFunctionalContextBaseCommon.executeMultipleToolsHacked
• which is called from two places: subtaskWithSingleToolMode and subtaskWithMultiToolMode

Both of these return immediately when the finish result is available:

// this happens in subtaskWithMultiToolMode
toolResults.firstOrNull { it.tool == finishTool.descriptor.name }
    ?.let { finishResult ->
        return finishResult.toSafeResult(finishTool, config.serializer).asSuccessful().result
    }

They don't have their version of finalizeTask that would append to prompt before returning, appending happened in this removed part here (so for these two scenarios we would end up with Tool.Call but without Tool.Result)

[EugeneTheDev]

Good catch, thanks, I will address it

[EugeneTheDev]

Updated subtasks in functional context too, added tests to verify

[Amaneusz]

LGTM, thanks!