MQTT connection not automatically reconnecting after unexpected AWS hangup

[eman]

Summary

After an unexpected MQTT hangup (AWS_ERROR_MQTT_UNEXPECTED_HANGUP), the library does not automatically reconnect. The CONNECTION_INTERRUPTED event is fired, but CONNECTION_RESUMED never fires. The connection remains dead until the application is manually restarted.

Steps to Reproduce

1. Run ha_nwp500 integration for several days
2. Wait for an unexpected connection hangup to occur (appears to happen daily around 3:43 AM)
3. Observe logs showing CONNECTION_INTERRUPTED event
4. No CONNECTION_RESUMED event is emitted
5. Device sensors become unavailable

Expected Behavior

• After CONNECTION_INTERRUPTED event, automatic reconnection should attempt to restore the connection
• CONNECTION_RESUMED event should fire when reconnection succeeds
• If automatic reconnection fails, it should retry with exponential backoff

Environment

• nwp500-python: (eval branch)
• AWS IoT Core MQTT endpoint: a1t30mldyslmuq-ats.iot.us-east-1.amazonaws.com

Error Pattern

Connection interrupted (no reconnection follows):

2026-05-12 03:43:21.926 WARNING [nwp500.mqtt.reconnection] Connection interrupted: AWS_ERROR_MQTT_UNEXPECTED_HANGUP: The connection was closed unexpectedly.

The connection remains down until manual restart.

[eman]

Fixed in commits ac440a4 and 37e8e5f on the eval branch (PR #82).

Root cause: _on_connection_resumed_internal was missing the connection parameter that the AWS IoT SDK passes as the first argument to on_connection_resumed(connection, return_code, session_present, **kwargs). The mismatched signature caused a silent TypeError (swallowed by the AWS CRT C layer), so:

• self._connected was never set back to True after the SDK auto-reconnected
• connection_resumed event was never emitted
• The reconnection loop ran indefinitely, keeping sensors unavailable

Compare the two callbacks — on_connection_interrupted was correct all along:

# Correct — had connection + **kwargs
def _on_connection_interrupted_internal(self, connection, error, **kwargs): ...

# Bug — missing connection and **kwargs  
def _on_connection_resumed_internal(self, return_code, session_present): ...

The fix adds connection as the first parameter and **kwargs for forward-compatibility.