docs: developer guides for executors, Docker images, and workflows

[cursor]

Summary

Adds in-repo developer documentation for recently shipped subsystems that lacked contributor-facing guides.

Docs added/updated

Document	What it covers
docs/developer/README.md	Index of developer notes
docs/developer/runner-executors.md	local / docker / k8s executor strategies, config keys, env vars, OSS vs Pro
docs/developer/docker-images.md	server, runner, job, and helper images — roles, contents, CI publishing
docs/developer/workflows.md	Pro workflow model, execution, artifacts, REST API, UI routes
docs/developer/ha-cluster-dashboard.md	Admin cluster API, task-state snapshot/clear
deployment/docker/README.md	Job/helper image overview and local build commands
deployment/compose/README.md	Remove duplicate SQLite section
api-docs.yml	Workflow note node kind, stopped run status, POST …/runs/{run_id}/stop
README.md, CONTRIBUTING.md	Link to docs/developer/

Codepaths covered

• services/runners/executor_factory.go, util/config.go — runner executor configuration
• deployment/docker/job/, deployment/docker/helper/ — executor container images
• db/Workflow.go, api/router.go, pro_interfaces/workflow_*.go — workflows
• api/cluster.go — HA cluster dashboard API

Knowledge gaps addressed

• No prior in-repo guide for Docker/K8s executor config or the new job/helper images published by CI
• Workflows shipped with internal AGENTS/plans notes only — no contributor-facing architecture or API reference
• Workflow swagger was missing the stop endpoint and stopped status
• HA cluster dashboard docs from an earlier automation run were never merged

  

[jon4hz]

Maybe I'm mistaking but doesn't the docker/k8s runner not also enable usage of ansible execution environments?

This would allow users bringing their own EE, so that you don't have to mount a requirements.txt anymore in order to pull additional python dependencies.

For this to work, the image that runs the job should be overwritable at template level though, and from what I saw, you can currently just specify one image per runner, right?

If this was overwritable per template, it could be a big selling point for you guys, as everyone who is currently using AAP, already has an EE for their ansible.