* enhance: make theme color format uniform
All newly fetched instance theme colors will be uniformely formatted
as hashtag followed by 6 hexadecimal digits.
Colors are checked for validity and invalid colors are not handled.
* better input validation for own theme color
* migration to unify theme color formats
Fixes theme colors of other instances as well as the local instance.
* add changelog entry
Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
* also recognize "shortcut icon" favicon
Not using querySelector for this because it uses jsdom which might be slower.
Reversing the order because WHATWG says the last appropriate link should be used.
* also fetchIconUrl
* br
* improve readability
* fix
* フォールバックにhrefの評価を含める
* fix val name
* 将来的な拡張を考えたコードにした
Co-authored-by: tamaina <tamaina@hotmail.co.jp>
Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
