Peer layer:
- Stream peer messages with a partial-write queue instead of write_all, so a
large SharedFileListResponse over the non-blocking socket is no longer
truncated (third-party clients like SoulseekQt can now browse our shares).
- Bound the peer-init handshake with a read timeout and handle each accepted
connection on its own thread, so one stalled peer can't wedge the listener.
- e2e: third-party direct/brokered/large-share browse + stalled-peer coverage.
TUI:
- Uploads share the downloads table columns (real Speed) and the info pane now
renders details for a selected upload.
- Download progress bar counts only in-progress transfers and hides when idle.
- Always-visible unread badge (private messages + rooms) in the shortcuts bar,
self-drawn blink so it works under tmux.
- Persist the unread private-message count across restarts.