* fix(github-project): make linked PR numbers clickable
* fix: open linked pull requests at their exact URLs
* test: assert complete project relation cell text
* fix: clarify linked pull request controls and overflow
* Fix linked pull request focus clipping and overflow label
* Keep linked pull request overflow outside clipped values
* fix(github-project): center plain project cells and say what +N means
Drop the clickable linked PR numbers: the numbers stay plain text as
before. Plain text cells (repository, parent issue, linked pull requests,
sub-issue progress) now center vertically like the other cells, and the
linked PR overflow reads "+N more" instead of a bare "+N".
* fix(github-project): keep the linked PR "+N more" visible when numbers truncate