GreenWall GuildRoster Classic

## 1.2.0

**Safe pass-through preparation — phase 1 of 2**
- Split roster collection into prepare, commit and abort stages so failed or
  incomplete transports cannot advance synchronization bookkeeping.
- Added a bounded versioned transaction format (`BEGIN`, numbered `DATA`, and
  `COMMIT`) and receive-side staging. Nothing is merged until every chunk is
  present; malformed, conflicting, oversized and expired transactions are
  discarded without changing the visible roster.
- Added transaction capability announcements alongside the existing version
  exchange. Older clients safely ignore the new capability frame.
- Added transaction and future pass-through counters to `/gwgr status`.
- Kept manual broadcasts in the legacy wire format, and left whisper sync and
  local-guild fan-out unchanged for full backward compatibility. Automatic
  hardware-event pass-through remains disabled until phase 2.