Construct the tmux runtime and a terminal.Manager fed by the CDC
broadcaster, and hand it to httpd.New so the /mux WebSocket surface goes
live. httpd.New now runs after the CDC substrate so the broadcaster exists
when the manager subscribes; the listener still binds before running.json
is written, preserving fail-fast on port conflict. The manager is closed on
shutdown alongside the CDC pipeline and lifecycle stack.
Add internal/terminal: a transport-agnostic feature package that attaches
a PTY to a session's tmux pane and multiplexes the byte stream to WebSocket
clients, plus a session-state channel fed by the CDC broadcaster.
The PTY is reached through a small PTYSource interface (satisfied by the
tmux runtime adapter) and spawned via an injectable spawnFunc, so fan-out,
the 50KB replay ring, and re-attach resilience all test without a real
process, tmux, or network. A tmux-guarded integration test exercises the
real creack/pty path end-to-end.
Raw PTY bytes never touch the CDC change_log; only the sessions channel is
CDC-fed. Windows PTY spawning is stubbed pending a ConPTY path.
Pritom14