The status stream read the websocket synchronously. Beast's
expires_after() only applies to async operations, so when a printer
stopped sending, ws.read() blocked forever, and stop_status_stream()
joined that thread when the app closed. On Windows the stuck process
also froze the next launch through the shared WebView2 browser.
Run the whole stream on one io_context owned by the stream thread, and
have stop_status_stream() post an abort to it. A stop on an open
websocket sends a close frame and waits up to 1 s for the answer.
Keep-alive pings detect a dead printer, and the stream reconnects until
stopped, with the backoff capped at 32 s. When a quiet printer still
answers pings, its last status is sent again. The stream starts under
connect_mutex after a staleness check, and a stop from the stream's own
callback no longer joins its own thread.
The Moonraker tests move into test_moonraker_printer_agent.cpp.
Kris Austin
da4d766d46