system/ui: fix authentication callback and connection tracking

[deanlee]

trafficstars

Fixes critical bugs in the WiFi manager that were causing connection failures and missing password prompts:

1. Fixed authentication callback issues: incorrectly using non-existent variables causing runtime exceptions:

   def _on_need_auth(self):
     match self.state:
       case StateConnecting(network):  # This throws NameError: name 'network' is not defined
         self.state = StateNeedsAuth(network)
   

2. Improved connection state tracking:

   • Added _current_connection_ssid to track active connection attempts
   • Implemented proper cleanup when connections succeed or fail

3. Enhanced error handling:

   • Added fallback methods to identify networks needing authentication

These changes ensure authentication prompts appear reliably and WiFi connections establish correctly.