feat: docker-agent.yaml config autodiscovery

[joshbarrington]

Closes: #2435

This allows auto config file discovery for docker-agent.yaml and docker-agent.yml in the current working directory.

Currently docker agent new leverages an agentic "creator" to build and write the config yaml file to disk. Here we specificy the fixed name in the instruction as opposed to the arbitrary name it previously would generate.

[joshbarrington]

@aheritier would be good to get a review when you have time.

[joshbarrington]

@dgageot this is ready when you have time for review.

Currently it just leverages an agent to write the config file when running docker new, as that's the existing behaviour.

[dgageot]

Hi @joshbarrington, thanks for the contribution! I'm not sure I would mix the work on default agents with the creator agent. Also, maybe it's better to consider .agents/docker-agent.yaml or .agents/default-agent.yaml as the default agent. wdyt?

[joshbarrington]

@dgageot point 2 in issue #2435 is scaffolding with docker agent new - running this process already leverages the creator agent to generate a new agent yaml file based on the description provided by the user, it generates it with a random (in context) name.

This just means the output file will save as docker-agent.yaml instead. What do you think is a better alternative? We write the in-built defaults to a file?

My interpretation of the issue implied the docker-agent.yaml should live in the root of the working directory synonymous to what you expect with a docker-compose.yaml and running docker compose, but can move it over into .agents/ if you think is best.