* chore: Add the SPDX information to each file
Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.
* tweak format
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Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
* 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>