The niri IPC worker slept 1ms per event and never reconnected. Under an
event burst the per-event cap back-pressures the socket, niri fills its
send buffer and drops the stream; read_line then returns false, the
detached thread exits and the module freezes permanently.
Remove the per-event sleep so events drain as fast as they arrive, and
wrap the socket setup and read loop in a reconnect loop that backs off
and re-establishes the stream on drop. A running_ flag lets the thread
exit cleanly on teardown.
Fixes#5117.
Alex
6672e924df