feat(workflow): Gitea-Wiki als generierter Spiegel von docs/ (#192)

Konverter .gitea/scripts/wiki_mirror.py, Push-Skript wiki-push.sh, Job wiki-mirror in release.yml, Dispatch-Workflow wiki-mirror.yml und --check-Schritt in ci.yml. Version 9.0.0-beta.13.

Files changed:
- .gitea/scripts/wiki-push.sh
- .gitea/scripts/wiki_mirror.py
- .gitea/workflows/ci.yml
- .gitea/workflows/release.yml
- .gitea/workflows/wiki-mirror.yml
- CHANGES.md
- README.md
- VERSION
- docs/dev/development.md
- tools/chemenu/tests/test_wiki_mirror.py

Co-Authored-By: Claude Code <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

VERSION

@@ -1 +1 @@
-9.0.0-beta.12
+9.0.0-beta.13