chore(ai): add agent self-review and a CI check for agent-assisted PRs

Additional changes
Agents write a task plan to .scratch/<branch>/plan.md and self-review with code-review
Agents fix hard violations, report judgement calls and rerun the self-review before every push
Agents declare the review in a Self-review section of the pull request body
Add the ai-self-review workflow and scripts/check_pr_self_review.py for pull requests into main
Detect agents by Assisted-by or Anthropic Co-Authored-By trailers, body markers or the AI box
Fail only on a missing Self-review section or a missing, malformed or stale Reviewed SHA
Note an unticked AI-assisted box and malformed optional lines without failing
Comment on the pull request how to fix a failure and update that one comment on later runs
Show the same report in the job summary and accept Windows line endings in the body
Skip dependabot and release pull requests
Run on pull_request_target with the base branch's script, never pull request code
Add the pull request template: the pr skill's sections plus Checklist and Self-review
Require always valid optimization parameters in the energy-domain skill
Require datetimeutil for date and time handling in new and changed code in AGENTS.md
Require the Assisted-by trailer on agent commits in the commit-messages skill
Add tests for the check in tests/test_ai.py
Add GLOSSARY.md and the agent tracker docs in docs/agents/
Add decision record docs/adr/0001 with an ADR index in the docs toctree
Document the workflow in docs/develop/ai.md and CONTRIBUTING.md
Exclude docs/agents from Sphinx and PyMarkdown and ignore .scratch/
Document cz check instead of make gitlint for commit messages in docs/develop/ai.md

Assisted-by: Claude Code (claude-opus-5-5)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -133,6 +133,24 @@ enforce the [`Conventional Commits`](https://www.conventionalcommits.org) commit
 You may use [`commitizen`](https://commitizen-tools.github.io/commitizen) also to create a
 commit message and commit your change.
 
+### AI-assisted contributions
+
+You may use coding agents, but you are the author of what you propose and must review the complete
+change yourself. Pull requests that an agent wrote or co-wrote are checked by CI:
+
+- Every commit an agent wrote or co-wrote ends with the trailer
+  `Assisted-by: <tool> (<model id>)`, e.g. `Assisted-by: Claude Code (claude-opus-5-5)`.
+- Tick the "AI-assisted" box in the pull request template.
+- The pull request body ends with a `## Self-review` section from the agent's self-review. It names
+  the full SHA of the head commit it reviewed. Before every push, rerun the self-review and rewrite
+  the section, do not just edit the SHA; replace the body right after the push. Agents also add an
+  `Assisted-by:` line to the body, which marks the pull request as agent-assisted.
+
+CI checks that the section is present and names the current head commit; other problems are
+only noted. It cannot check the review itself. If the check fails, CI comments on the pull request
+with what is wrong and how to fix it. See `docs/develop/ai.md` (AI-assisted development) for the
+workflow and the exact format.
+
 ## Thank you!
 
 And last but not least thanks to all our contributors