Enables bd sync to work with local-only branches that don't have upstream tracking. Auto-detects this case and syncs beads from origin/main instead of requiring an upstream branch. Also fixes hasJSONLConflict() to recognize both issues.jsonl and beads.jsonl filenames. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>