feat(chat): show the workspace branch under the composer

[oxwen11]

Summary

• Port of pie#52: show the current git branch under the session composer.
• Adds a minimal git.branch RPC ({ cwd } → { current }). Non-git directories return current: null and the footer stays hidden. Query uses the route-resolved workspace path, not a sideways project lookup.

Test plan

• turbo run test --filter=@vibest/server -- rpc-git.test.ts
• Session whose cwd is not a git repo: composer loads, no branch footer
• Session whose cwd is a git repo: footer shows the current branch name

Made with Cursor

[github-actions]

React Doctor found 1 issue in 1 file · 1 warning · score 92 / 100 (Great) · full project

1 warning

src/features/chat/runtime/client-prompt-queue.ts

• ⚠️ L0 unused-file

_{Reviewed by React Doctor for commit f67c77d. See inline comments for fixes.}