feat(refresh-repo): auto-restore main worktree to main branch

[JacobPEvans]

Summary

Adds a step to the refresh-repo Sync Workflow that detects and fixes a
common workspace drift: the <repo>/main/ worktree left checked out to a
now-[gone] feature branch after that branch's PR merged.

This violates the convention in ~/git/CLAUDE.md:

Main worktree always at ~/git/<repo>/main/ on the main branch.

A workspace sweep observed this drift in four repos: docs,
dryvist-dotgithub, dryvist-dotgithub-tofu, and tf-splunk-aws.

Behavior

In Step 3 (Sync Workflow), immediately after the default-branch is
resolved and before the fast-forward merge:

• Resolve the default-branch worktree path from git worktree list.
• If git -C <path> symbolic-ref --short HEAD is not the default branch:
  • If the worktree has uncommitted changes (git status --porcelain
    is non-empty), stash them with a recoverable label
    (refresh-repo: auto-stash before <default> restore) and surface
    the stash ref in the summary.
  • git -C <path> checkout <default>.
• Never --force, never reset, never discard uncommitted work.

The existing fast-forward merge now runs on the restored default branch
instead of failing or no-op'ing on the wrong head.

Test plan

• Manually drop <repo>/main/ onto a [gone] feature branch and
  run /refresh-repo; verify it stashes (if dirty), checks out
  main, and fast-forwards.
• Run /refresh-repo on a repo where <repo>/main/ is already on
  main and verify no-op behavior (no extra stash, no unnecessary
  checkout).
• Run on a repo with a dirty main/ worktree on a feature branch
  and confirm the stash reference is reported.

[gemini-code-assist]

Code Review

This pull request updates the refresh-repo skill documentation to include a new step for restoring the default-branch worktree, including logic for stashing uncommitted changes and checking out the default branch. Review feedback suggests several improvements for robustness and policy compliance: using explicit paths instead of basenames to avoid ambiguity, replacing symbolic-ref with rev-parse to handle detached HEAD states, ensuring sync commands target the specific worktree path using git -C, and removing unnecessary branch-switching steps to adhere to worktree management conventions.

[gemini-code-assist]

Matching the worktree by basename is ambiguous. For example, a feature branch named feature/main would have a worktree path like ~/git/<repo>/feature/main/, which also has the basename main. Additionally, in a bare-repo setup, the repository root itself might match if the repo is named main. It is safer to resolve the path using the explicit convention: ~/git/<repo>/<default>/.

Suggested change

	- Resolve the default worktree path from `git worktree list` — the entry whose
	path basename matches the default branch (e.g. `<repo>/main` for `main`).
	- Resolve the default worktree path using the workspace convention:
	~/git/<repo>/<default>/

[gemini-code-assist]

The sync command in the following line must be updated to use the <path> resolved in Step 4. Per the repository's general rules, syncing a branch in a worktree setup should be done by executing commands within its dedicated directory. Without git -C <path>, if the user is currently in a feature worktree, the merge will incorrectly target the feature branch instead of the default branch.

References

1. In a git worktree setup where each branch has a dedicated directory, sync a branch by executing git commands from within its worktree directory, rather than using git switch to change branches in the current worktree.

[gemini-code-assist]

This step suggests switching branches, which is discouraged in a git worktree setup. According to the repository rules, we should execute commands within the dedicated worktree directory instead of using git switch. If Step 4 is implemented by navigating to the correct directory or using git -C, this 'switch back' step should be removed to avoid violating the worktree management policy.

Suggested change

	7. Switch back to the original branch if it still exists.
	7. Conclude the operation without switching branches, as each worktree has a dedicated directory.

References

1. In a git worktree setup where each branch has a dedicated directory, sync a branch by executing git commands from within its worktree directory, rather than using git switch to change branches in the current worktree.

[gemini-code-assist]

Using git symbolic-ref --short HEAD will cause an error if the worktree is in a detached HEAD state (e.g., during a rebase or if a specific commit is checked out). Using git rev-parse --abbrev-ref HEAD is more robust as it returns the branch name or HEAD without failing.

Suggested change

	- If that path exists and `git -C <path> symbolic-ref --short HEAD` does not equal
	- If that path exists and git -C <path> rev-parse --abbrev-ref HEAD does not equal