Commit, compare and SHA links render the SHA in code with the rest of
the URL after it, and links to other repositories get an `owner/repo@`
prefix like references do.
- Abbreviated SHAs, branch compares and `<url>` autolinks now render as
commit links
- Pull request commit URLs no longer break into an issue reference plus
stray text
- Only routes that take a SHA are shortened, so file and API URLs stay
plain
Replaces https://github.com/go-gitea/gitea/pull/36725
<img width="620" alt="Commit links before and after"
src="https://github.com/user-attachments/assets/5919c8a0-94e3-4148-ad11-6944bf790572"
/>
51879941dc