feat(client): ratatui TUI subscribing to SDK events
Single-file v2 TUI (v2_tui.rs, ~580 lines) gated behind
cfg(all(feature = "v2", feature = "tui")).
Layout: conversations sidebar, scrollable messages panel,
input bar with cursor editing, status line. Help overlay
on /help. Subscribes to SDK broadcast::Receiver<ClientEvent>
for real-time updates. TerminalGuard ensures terminal restore
on panic. Commands: /login, /register, /logout, /dm, /group,
/quit, /help.
Build: cargo build -p quicproquo-client --features v2,tui
Christian Nennemann
99f9abe9ed