The previous image versions set ANSIBLE_WORKER_SESSION_ISOLATION=False in an
attempt to restore SSH prompts on Ansible 2.21. That setting does not bring
the prompts back — it makes Ansible hang silently at the first SSH connection
whenever a prompt would have been needed. See
https://github.com/devture/docker-ansible/issues/6

The new image auto-accepts the SSH host keys of previously unknown hosts
instead. The docs stop recommending ANSIBLE_WORKER_SESSION_ISOLATION=False
for direct (non-Docker) runs for the same reason, and now explain how to use
an ssh-agent for passphrase-protected SSH keys.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

The new image includes py3-regex.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

The new image restores the ability of SSH to ask about unknown host keys
and to prompt for the passphrase of an SSH key, which Ansible 2.21 broke
by having forked workers run session-isolated.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

- add SPDX licensing information for REUSE compliance
- drop the JSONC comment from devcontainer.json, keeping it strict JSON
  (as required by the check-json pre-commit hook)
- bump the base image to the current ghcr.io/devture/ansible release
- mention the dev container in docs/ansible.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>