Pull Request Pages, Reviewers, Reactions, Micro Sandboxes, and Session Rename

#A dedicated pull request detail page

Tembo now has a pull request detail page with richer review context, including review comment threads in the right sidebar. Reviewing agent work is more complete without leaving the product.

#Pull request reviewers and reactions

We added reviewer tracking, requested-reviewer support, PR comment reactions, and resolved or unresolved review thread sync. Tembo now understands more of the collaboration that happens around a pull request.

#Pull request descriptions update after feedback

Tembo can now update pull request descriptions after feedback, keeping the PR summary closer to the current state of the work as the session evolves.

#Micro sandbox size

We added a micro sandbox size for smaller tasks that do not need a larger environment, helping teams pick a more appropriate compute profile for lightweight sessions.

#Rename sessions from the header

Sessions now include a rename option in the header menu, plus persistent task filters and a clearer running-session indicator for everyday navigation.

Also various bug fixes and improvements as always :)