Add wiki sync: docs/ stays the source of truth, wikis auto-mirror (#4)

scripts/sync-wiki.ps1 clones a wiki repo, copies+flattens markdown
from docs/ with a slug mapping (e.g. recipes/zerto-pre-post-scripts.md
becomes the Recipe-Zerto-Failover page), rewrites in-repo markdown
links to wiki-style targets, generates a _Sidebar.md, and pushes back
if anything changed. Idempotent.

.github/workflows/wiki-sync.yml runs the sync on every push to main
that touches docs/ (or the sync tooling itself). Uses GITHUB_TOKEN
which has wiki write access via the contents:write permission.

For Gitea, no Windows runner is available, so the script is invoked
manually with a Gitea PAT in the URL. One-time setup for each remote:
enable Wiki in repo settings, create a Home page via the web UI to
initialize the wiki repo, then run the sync.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/wiki-sync.yml

@@ -0,0 +1,27 @@
+name: Sync Wiki
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'docs/**'
+      - 'scripts/sync-wiki.ps1'
+      - '.github/workflows/wiki-sync.yml'
+  workflow_dispatch:
+
+jobs:
+  sync:
+    runs-on: windows-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Sync docs/ to GitHub wiki
+        shell: pwsh
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          $repo = '${{ github.repository }}'
+          $wikiUrl = "https://x-access-token:$env:GH_TOKEN@github.com/$repo.wiki.git"
+          ./scripts/sync-wiki.ps1 -WikiUrl $wikiUrl