fix: expand auto-resolve patterns and add missing forks to dispatch

- Auto-resolve .env.example (keep fork's channel-specific vars) and
  .github/workflows/* (always take upstream) during fork sync
- Add docker-sandbox and docker-sandbox-windows to dispatch list

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/fork-sync-skills.yml

@@ -67,10 +67,15 @@ jobs:
             AUTO_RESOLVABLE=true
             for f in $CONFLICTED; do
               case "$f" in
-                package-lock.json|package.json|repo-tokens/badge.svg)
+                package-lock.json|package.json|repo-tokens/badge.svg|.github/workflows/*)
                   git checkout --theirs "$f"
                   git add "$f"
                   ;;
+                .env.example)
+                  # Keep fork's channel-specific env vars
+                  git checkout --ours "$f"
+                  git add "$f"
+                  ;;
                 *)
                   AUTO_RESOLVABLE=false
                   ;;