ci: sync windy-chat + windy-mail, bridge PR CI verdicts back to GitHub

GitHub Actions can't run on the private platform repos. Windy Git already
has their code and a working runner, so:

- windy-chat and windy-mail were read-only pull mirrors (which can never
  run Actions); they are now writable, deploy.yml/build-image.yml disabled,
  and synced from GitHub like the others.
- scripts/pr_status_bridge.py mirrors open same-repo GitHub PRs into Windy
  Git (so pull_request workflows fire) and posts each job's result back as
  a GitHub commit status (windy-git/<workflow>/<job>) on PR heads and the
  default-branch head. Fork PRs are never run. Runs after every sync.

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="${SYNC_REPOS:-windy-calendar windy-search windy-registry Windy-Clone WindyCloud windy-cloud-sites windy-mind eternitas windy-agent windy-git}"
+REPOS="${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}"
 
 mkdir -p "$WORK"
 log() { printf '[sync %s] %s\n' "$(date -u +%H:%M:%SZ)" "$*"; }
@@ -70,5 +70,11 @@ for r in $REPOS; do
   fi
 done
 
+# Private repos can't run GitHub Actions; mirror their open PRs here so CI
+# fires, and post the verdicts back to GitHub as commit statuses.
+if ! python3 "$(dirname "$0")/pr_status_bridge.py"; then
+  log "FAILED pr status bridge"; FAILED=1
+fi
+
 [[ "$FAILED" -ne 0 ]] && { log "COMPLETED WITH FAILURES"; exit 1; }
 log "all repos in step with GitHub"