Fix stop() leaving ghost threads that block reconnection

[Fernandosnulerin]

Summary

Fixes #71.

When stop() is called, the backend event stream thread keeps running — it holds stale SSE/MQTT connections and attempts its own re-logins, making it impossible to create a new PyArlo instance in the same process. The only recovery is killing the entire process.

Three bugs contributed:

1. PyArlo.stop() never stops the backend — it only calls self._be.logout() when logout=True. With the default logout=False, the event stream thread is never stopped.

2. The re-login loop ignores the stop flag — _event_main() has while not self._logged_in without checking _stop_thread. Once the event stream drops, the thread enters an infinite re-login loop that cannot be interrupted by stop().

3. _event_stop_loop() doesn't wake blocked threads — it sets the flag but doesn't call notify_all(), so threads blocked on self._lock.wait(5) don't see it for up to 5 seconds.

Changes

• Add ArloBackEnd.stop() — signals the event thread, disconnects the MQTT/SSE client, and joins the thread with a 10s timeout
• Update PyArlo.stop() to always call self._be.stop() (or .logout() when logout=True)
• Check _stop_thread in the re-login loop so stop requests are honoured immediately
• Call self._lock.notify_all() in _event_stop_loop() to wake blocked threads

Motivation

Any long-running application that needs to reconnect to Arlo (e.g. Home Assistant, or any polling service) hits this — after the session goes stale, creating a new PyArlo instance in the same process fails because the old instance's ghost threads compete for the same Arlo account, triggering Cloudflare 403/500 blocks. The standard workaround has been to restart the entire process, but proper cleanup in stop() makes in-process reconnection work reliably.

Test plan

• Call arlo.stop() then verify ArloBackgroundWorker and ArloEventStream threads are no longer alive
• Call arlo.stop(logout=True) then create a new PyArlo() in the same process — should connect cleanly
• Call arlo.stop() while the event thread is in the re-login loop — thread should exit promptly

🤖 Generated with Claude Code