Some printer MQTT brokers (e.g. P1S) reject subscriptions to the request
topic by killing the TCP connection, causing a disconnect loop. The request
topic subscription for ams_mapping capture is now fail-safe with two
detection paths:
- SUBACK rejection: on_subscribe callback detects failure code 0x80
- Broker kills connection: on_disconnect detects disconnect within 10s of
unconfirmed subscription attempt
After detection, the request topic is disabled for that printer and
reconnection succeeds with only the report topic. Printers that support
the request topic (e.g. X1E, H2D) get ams_mapping capture; printers that
don't (e.g. P1S) gracefully degrade to tray_now-based tracking.