[Nailik]

Summary

Every failure while connecting or validating the PIN during setup, reauth or reconfigure ended up as error_unknown ("Failed to connect to the device: …"). The failures a user can act on now get their own message.

Failure	Error key	Message (en)
BleakNotFoundError, device went away between discovery and connecting	error_device_not_found (existing)	Device not found. Please ensure the Blanco Unit is powered on and in Bluetooth range.
BleakOutOfConnectionSlotsError	error_no_connection_slot (new)	No free Bluetooth connection slot. Disconnect another Bluetooth device from the adapter or proxy, or add a Bluetooth proxy, then try again.
BlancoUnitGattTimeoutError, still stuck after reconnecting (and removing the device from BlueZ on a local adapter)	error_device_not_responding (new)	The Blanco Unit did not respond over Bluetooth, even after reconnecting. Reboot the Home Assistant host (restarting only Home Assistant is not enough) or restart the Bluetooth proxy, then try again. If that does not help, restart the Blanco Unit.
BlancoUnitConnectionError (including the new BlancoUnitProtocolError), BleakError, OSError, TimeoutError	error_connection (new)	Communication with the Blanco Unit failed. Please move it closer to the Bluetooth adapter or proxy and try again. ({error})
anything else	error_unknown	An unexpected error occurred: {error}

• {error} now includes the exception type (TimeoutError, BleakError: …), since a TimeoutError has no message of its own.
• A response the device sends that cannot be parsed (Invalid chunk stream, Chunk message ID mismatch, Failed to parse JSON response) raised ValueError before. The config flow maps ValueError to invalid_pin_format, so it was shown as "PIN must be exactly 5 digits", although the PIN format is checked before connecting. parse_response now raises BlancoUnitProtocolError, a BlancoUnitConnectionError, which ends up as error_connection.
• The not responding message points at the host (BlueZ) or the proxy first, since that is where a stuck GATT operation lives.
• All new keys are in en.json and de.json.
• A wrong PIN still shows error_invalid_authentication. validate_pin reports it as a result, not as an exception, so nothing changes there.

Besides config_flow.py, the two translation files and tests/test_config_flow.py, only parse_response in client.py (and its tests) changes.

Test plan

• pytest tests: 383 passed, 68 snapshots passed
• A garbled response through the real validate_pin and parse_response shows error_connection, not invalid_pin_format
• New parametrized test covers each mapping, raised where it really comes from (connecting or the PIN check)
• Read the new strings in the setup dialog, in English and German

🤖 Generated with Claude Code