Proposal: rename "issues" to "tickets"

This is inspired by the post https://nesbitt.io/2026/05/02/a-github-for-maintainers.html#rename-issues, which states:

...a feature request isn’t a problem, a question isn’t a problem, and calling everything that arrives in a maintainer’s inbox an “issue” sets the temperature of the conversation before anyone’s typed a word. I think it contributes more than people realise to the ambient hostility of running a popular project. “Tickets” is boring and neutral and that’s the point.

I understand the inclination to lean towards GitHub's terminology for consistency and portability for users moving from GitHub, but I think they made a mistake with that naming and there is a good way for Tangled to differentiate! Tickets is neutral instead of holding a negative connotation, and, for me at least, imply a more actionable state — iirc his is another change that the Ghostty project made along with vouching, to only have "issues" open for the solvable, fixable tasks - these are tickets.