[feature]: Copy / View changes as `.diff`

[gameroman]

Describe the feature

A button to view/copy change as a .diff on a /diff pagge

Similar to github's .diff view on a PR, for example:

https://github.com/npmx-dev/npmx.dev/pull/3017 ⬇️
https://github.com/npmx-dev/npmx.dev/pull/3017.diff

Additional information

• Would you be willing to help implement this feature?

Final checks

• Read the contribution guide.
• Check existing issues.

[mootari]

TIL that .diff works too, I was only aware of .patch. Which one is the canonical form though?

Nvm, .patch is definitely the wrong choice here. Sorry for the noise!

[gameroman]

TIL that .diff works too, I was only aware of .patch. Which one is the canonical form though?

They're different things, .diff just shows the diff, .patch shows extra metadata

.patch makes no sense for an npm package I think so we only need the .diff