feat(gui): add activity calendar to the homepage

[ellie]

Might need to re-org or change the colour scheme, but it's there

The SQLite query has been tested on a variety of machines and seems to perform well across the board!

Checks

• [ ] I am happy for maintainers to push small adjustments to this PR, to speed up the review cycle
• [ ] I have checked that there are no existing pull requests for the same thing

[atuin-bot]

This pull request has been mentioned on Atuin Community. There might be relevant details there:

https://forum.atuin.sh/t/allow-to-override-automatic-localization/381/1