Issue Title: Discovery error: KH100 Hub (with Kasa protocol) triggers `Failed to determine the right tapo protocol`

[mulle78de]

Description

The automatic discovery process triggers an error in the logs when detecting the KH100 Smart IoT Hub. While the H100 Smart Hub works flawlessly, the KH100 seems to use the Kasa-based/unified discovery mechanism, causing the Tapo integration to pick it up mistakenly. The setup then fails during the protocol negotiation phase with a CannotConnect exception.

Steps to Reproduce

1. Have a KH100 Hub active in the same local network.
2. Allow Home Assistant to automatically discover the device via the tapo custom component.
3. The configuration flow triggers an error during the async_step_discovery_auth_confirm phase.

Error Log / Traceback

Logger: custom_components.tapo.config_flow
Quelle: custom_components/tapo/config_flow.py:229
Integration: TP-Link Tapo
Erstmals aufgetreten: 09:49:11 (6 Vorkommnisse)
Zuletzt protokolliert: 09:56:51
Failed to setup cannot connectTraceback (most recent call last):
  File "/config/custom_components/tapo/config_flow.py", line 318, in _async_get_device
    device = await connect_discovered_device(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        discovered_device, credential, session
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/usr/local/lib/python3.14/site-packages/plugp100/discovery/service.py", line 43, in connect_discovered_device
    return await connect(config, session)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/plugp100/devices/factory.py", line 55, in connect
    protocol = await _get_or_guess_protocol(config, session)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/plugp100/devices/factory.py", line 80, in _get_or_guess_protocol
    raise Exception("Failed to determine the right tapo protocol")
Exception: Failed to determine the right tapo protocol

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/config/custom_components/tapo/config_flow.py", line 229, in async_step_discovery_auth_confirm
    device = await self._async_get_device_from_discovered(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        self._discovered_info, user_input
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/config/custom_components/tapo/config_flow.py", line 295, in _async_get_device_from_discovered
    return await self._async_get_device(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        config | {CONF_HOST: discovered.ip}, discovered
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/config/custom_components/tapo/config_flow.py", line 328, in _async_get_device
    raise CannotConnect from error
custom_components.tapo.errors.CannotConnect

[poita66]

@mulle78de Would you be interested in trying my fork to see if it helps you?

[mulle78de]

Hi @poita66, I will test in a week, I am away at the moment. Thanks for implementing it.

[mulle78de]

@poita66

I was able to test commit c281777.

Here is what I observed:

1. Tapo H100 (IP .112): Successfully discovers the 3 child devices, though it throws error -1402 during update coordinator polling (update.py).

2. Kasa KH100 Hub (IP .193): Can now be added to HA, but it seems HA does not treat it as a Hub yet:

   • There are no KLAP handshakes or child discovery attempts triggered for this IP in the logs at all.
   • It appears the integration might be recognizing the KH100 as a standalone device rather than a hub coordinator, so the child device polling logic is never executed for it.

Here is the log snippet for the H100 update polling error (-1402) for reference:

2026-08-03 09:38:26.377 DEBUG (MainThread) [plugp100.api.protocol.klap.klap_protocol] [KLAP] Handshake with [http://192.168.178.112:80/app](http://192.168.178.112:80/app) complete
2026-08-03 09:38:26.466 ERROR (MainThread) [custom_components.tapo.coordinators] Tapo exception: Returned unknown error_code: -1402  msg: curr ver:1.5.5 Build 20230927 Rel. 40646, cloud ver:.
2026-08-03 09:38:26.467 ERROR (MainThread) [custom_components.tapo.coordinators] Error fetching tapo data: Error tapo exception: Returned unknown error_code: -1402  msg: curr ver:1.5.5 Build 20230927 Rel. 40646, cloud ver:.
2026-08-03 09:38:26.467 DEBUG (MainThread) [custom_components.tapo.coordinators] Full error:
  File "/config/custom_components/tapo/coordinators.py", line 83, in _async_update_data
  File "/config/custom_components/tapo/update.py", line 74, in poll_update
  File "/usr/local/lib/python3.14/site-packages/plugp100/common/functional/tri.py", line 169, in get_or_raise
plugp100.api.transport.exceptions.TapoException: Returned unknown error_code: -1402  msg: curr ver:1.5.5 Build 20230927 Rel. 40646, cloud ver:.