Improve logging for http component/documentation of "Can only log in from the local network"

If you attempt to log on from an IPv6 address and the user does not have “Can only log in from the local network” ticked, it won’t work.

The user settings page doesn’t explain that IPv6 is a “special case” when it comes to what the “local network” is. I can’t actually find any documentation that explains this. There are only two hits on this at www.home-assistant.io:

https://www.google.com/search?q=site%253Awww.home-assistant.io+"Can+only+log+in+from+the+local+network"

The log message does not say why the log in attempt failed. It implies it has failed because the credentials are incorrect, but they are not. The components.http.ban bit implies the IP is banned but I have that feature disabled.

2024-05-30 22:48:46.297 WARNING (MainThread) [homeassistant.components.http.ban] Login attempt or request with invalid authentication from 2001:xx (2001:xx). Requested URL: '/auth/login_flow/902b2021d306a67f0b699365c042c5c9'. (Mozilla/5.0 (Linux; Android 5.1.1; KFFOWI Build/LVY48F; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/59.0.3071.125 Safari/537.36 Home Assistant/2024.4.1-12576 (Android 5.1.1; KFFOWI))

Documentation updates don’t really get [FR]'s, people just do them. It sounds to me that your request is to document this better.
If this is not the case, maybe you were not clear enough.

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The log message does not say why the log in attempt failed. It should say why the attempt failed. “invalid authentication” is too vague.