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>

AGENTS.md

@@ -25,6 +25,18 @@ maintainable code, testability, and type safety.
   management.
 - Preserve compatibility with existing tests and supported integrations unless
   a change explicitly requires otherwise.
+- **Create, parse, convert and compare dates, times, durations and time zones
+  with `akkudoktoreos.utils.datetimeutil`** (`to_datetime`, `to_duration`,
+  `to_timezone`, `to_time`, `compare_datetimes`, `DateTime`, `Duration`). Do not call
+  `datetime`, `pendulum` or `dateutil` directly. Exceptions: `datetimeutil.py`
+  itself, and boundaries where a third-party API needs its own type (pandas,
+  NumPy, the standard library), converted right at the boundary. Applies to new
+  and changed code; migrate existing direct calls only where the change touches
+  them anyway.
+- **Optimization parameters are always valid**: their preparation never fails
+  and never cancels an optimization run. See the `energy-domain` skill.
+- Commits written or co-written by an agent end with the trailer
+  `Assisted-by: <tool> (<model id>)`, see the `commit-messages` skill.
 - Never use the workspace `.venv`: run `uv`, `make` and all Python tools in a
   virtual environment outside the workspace (`UV_PROJECT_ENVIRONMENT`), see
   `ai/skills/python-environment/SKILL.md`.
@@ -79,6 +91,62 @@ Load these only when the user asks for them by name:
 | `ai/skills/engineering/triage/SKILL.md` | Triage issues and external PRs |
 | `ai/skills/engineering/wayfinder/SKILL.md` | Plan large work as decision tickets |
 
+## Task plan and self-review
+
+- Before writing code for a task beyond a small fix, agree on a plan with the
+  user and write it to `.scratch/<branch>/plan.md` (the **task plan**, see
+  `GLOSSARY.md`). `.scratch/` is ignored by git; never commit it. Keep the plan
+  up to date when the user changes the task.
+- When the task is done, run the **self-review**: the `code-review` skill
+  against the base branch (usually `main`). The spec is the GitHub issue the
+  commits reference, if any, otherwise the task plan.
+- The coding standards for the review are `CONTRIBUTING.md`, this file and the
+  project skills in `ai/skills/` (not `ai/skills/engineering/`).
+- Fix every **hard violation** (breach of a documented project rule) yourself,
+  rerun the checks and the self-review. Report **judgement calls** (code
+  smells, possible scope creep) to the user without acting on them.
+- Write the pull request body to `.scratch/<branch>/pr.md` with the `pr` skill,
+  in the structure of `.github/pull_request_template.md`: the skill's
+  `## Summary`, `## Evidence` and `## Merge Danger` (with optional
+  **Breaking:** and **Security:** lines), then `## Checklist` with the
+  "AI-assisted" box ticked. It ends with a `## Self-review` section in
+  exactly this format. CI requires the `Reviewed:` line and notes problems
+  with the others, see `docs/develop/ai.md`:
+
+  ```markdown
+  ## Self-review
+
+  Reviewed: <full 40-character SHA of the reviewed HEAD commit>
+  Base: <base branch or commit>
+  Standards: <n> hard, <m> judgement
+  Spec: <k> open (source: <#issue | .scratch/<branch>/plan.md | none>)
+
+  - <one line per open finding or judgement call, and why it was left>
+
+  Assisted-by: <tool> (<model id>)
+  ```
+
+  Keep footers the tool adds itself below it, e.g. Claude Code's
+  `Generated with [Claude Code](https://claude.com/claude-code)`.
+
+- The self-review runs once at the end of the task, not before every commit.
+  Before every push (e.g. of fixes after review feedback), rerun the
+  self-review and rewrite the section in `.scratch/<branch>/pr.md`; never
+  just edit the SHA. The `Reviewed:` SHA must be the head of the pull
+  request. The pull request body is replaced right after the push.
+
+## Agent skills
+
+### Issue tracker
+
+GitHub issues of the upstream repository `Akkudoktor-EOS/EOS`. See
+`docs/agents/issue-tracker.md`.
+
+### Domain docs
+
+Single-context: `GLOSSARY.md` and `docs/adr/` at the repository root. See
+`docs/agents/domain.md`.
+
 ## Completion checklist
 
 Before considering a change complete:
@@ -91,3 +159,5 @@ Before considering a change complete:
 - [ ] Mypy checks pass where applicable.
 - [ ] Configuration and documentation updated when necessary.
 - [ ] No unrelated changes or unnecessary exceptions introduced.
+- [ ] Self-review done, hard violations fixed, judgement calls reported.
+- [ ] `.scratch/<branch>/pr.md` holds an up-to-date `## Self-review` section.