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

.gitea/workflows/release.yml

@@ -17,6 +17,13 @@
 # instance issues - not a 1Password secret. Nothing here reaches outside the
 # instance, so the Zero-Trust secret path that the container-build workflows
 # use has nothing to carry.
+#
+# `wiki-mirror` is the second job: once `release` has published a release, it
+# mirrors that tree's docs into the Gitea wiki (.gitea/scripts/wiki_mirror.py
+# converts, wiki-push.sh pushes; wiki-mirror.yml does the same by hand for any
+# tag). It is a separate job so that a failing mirror leaves the release and its
+# tag standing: the release is the product, the wiki a view of it. It does not
+# run for a `-beta.N` candidate, for which `release` sets `skip`.
 
 name: Release
 
@@ -38,6 +45,10 @@ jobs:
       image: debian:trixie-slim
     permissions:
       contents: write
+    outputs:
+      skip: ${{ steps.version.outputs.skip }}
+      version: ${{ steps.version.outputs.version }}
+      tag: ${{ steps.version.outputs.tag }}
     env:
       WIKITOOL_SESSION_ID: release-${{ github.run_id }}
       WIKI_TRACE_DIR: /tmp/wikitool-trace
@@ -233,3 +244,43 @@ jobs:
           done
 
           echo "Done: ${PUBLIC_BASE_URL}/${GITHUB_REPOSITORY}/releases/tag/${TAG}"
+
+  wiki-mirror:
+    # Runs only after `release` succeeded and created a release (a candidate
+    # sets skip=true). `release` never depends on this job.
+    needs: release
+    if: needs.release.outputs.skip != 'true'
+    runs-on: linux-docker
+    container:
+      image: debian:trixie-slim
+    permissions:
+      contents: write
+    env:
+      VERSION: ${{ needs.release.outputs.version }}
+      TAG: ${{ needs.release.outputs.tag }}
+      PUBLIC_BASE_URL: https://gitea.nehmer.net
+
+    steps:
+      - name: System dependencies
+        run: |
+          set -eu
+          apt-get update -qq
+          apt-get install -y --no-install-recommends python3 git nodejs ca-certificates curl jq
+          rm -rf /var/lib/apt/lists/*
+
+      - uses: actions/checkout@v7
+
+      - name: Mirror the docs into the wiki
+        env:
+          WIKI_TOKEN: ${{ gitea.token }}
+        run: |
+          set -eu
+          python3 .gitea/scripts/wiki_mirror.py --source . --out /tmp/wiki-out \
+            --version "$VERSION" --repo-url "${PUBLIC_BASE_URL}/${GITHUB_REPOSITORY}"
+          .gitea/scripts/wiki-push.sh /tmp/wiki-out "$VERSION"
+
+      - name: Say which half failed
+        if: failure()
+        run: |
+          echo "Release ${TAG} is published; only the wiki mirror failed."
+          echo "The release and its tag stand. Dispatch wiki-mirror.yml with tag ${TAG} to retry the mirror."