ci: G11.5 resolved — onboard windy-pro; cloud cells + windytalk; promote script

- import_from_github.py no longer refuses windy-pro: lane 8c audited all
  14 checkouts (WINDYPRO_CHECKOUTS.md), GitHub main is canonical.
- sync + bridge: windy-cloud-domains, windy-cloud-vps, windytalk (default
  branch master), windy-pro; windy-cloud-sites added to the bridge (it was
  synced but never bridged).
- scripts/promote_to_ci.sh: the mirror->writable procedure as one script,
  with the delete-before-import hazard documented.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/sync_from_github.sh

@@ -38,7 +38,7 @@ FAILED=0
 
 # Repos Windy Git tracks FROM GitHub. Remove a repo from this list at the moment
 # it flips to Windy-Git-first, or the sync will fight its authors and win.
-REPOS="${SYNC_REPOS:-windy-calendar windy-search windy-registry Windy-Clone WindyCloud windy-cloud-sites windy-mind eternitas windy-agent windy-git windy-chat windy-mail windy-connect windy-drops windy-code-web windy-code windy-traveler windy-translate windytranslate-site windytraveler-site windy-hand}"
+REPOS="${SYNC_REPOS:-windy-calendar windy-search windy-registry Windy-Clone WindyCloud windy-cloud-sites windy-mind eternitas windy-agent windy-git windy-chat windy-mail windy-connect windy-drops windy-code-web windy-code windy-traveler windy-translate windytranslate-site windytraveler-site windy-hand windy-cloud-domains windy-cloud-vps windytalk windy-pro}"
 
 mkdir -p "$WORK"
 log() { printf '[sync %s] %s\n' "$(date -u +%H:%M:%SZ)" "$*"; }