fix(tui): show detached HEAD in git status

[lurenjia534]

Related Issue

Resolve #566

Problem

See linked issue. In a detached HEAD checkout, git branch --show-current returns an empty string even though the working directory is still a valid git repository. The footer could therefore drop useful git context instead of showing which commit is checked out.

What changed

• Fall back to git rev-parse --short HEAD when no branch name is available and display detached@<short-sha>.
• Treat detached HEAD as a no-branch state for pull request lookup so stale branch PR results cannot appear in the footer.
• Add regression coverage for detached HEAD display and stale pull request callbacks after switching from a branch to detached HEAD.

Verification

• corepack pnpm vitest run apps/kimi-code/test/utils/git/git-status.test.ts
• corepack pnpm --filter @moonshot-ai/kimi-code run typecheck
• corepack pnpm lint (515 warnings, 0 errors; warnings are existing repository-wide lint warnings)
• Built the full CLI with corepack pnpm --filter @moonshot-ai/kimi-code run build and manually verified the footer in a detached checkout

Note: full corepack pnpm test was also run locally on Windows before opening this PR and failed on unrelated existing Windows/path/process snapshot failures; the focused regression test above passes.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 5166916

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

pnpm dlx https://pkg.pr.new/@moonshot-ai/kimi-code@5166916

npx https://pkg.pr.new/@moonshot-ai/kimi-code@5166916

commit: 5166916