Fix: Enable HEAD resolution in git worktrees

[meekrosoft]

Summary

Enable EnableDotGitCommonDir option in gitview.New() to properly resolve HEAD references in git worktrees.

Changes

• Modified gitView.New() to use git.PlainOpenWithOptions() with EnableDotGitCommonDir: true
• Added comprehensive test TestNewGitViewFromWorktree() that validates:
  • Creating GitView from a worktree path succeeds
  • BranchName() returns correct branch in worktree context
  • GetCommitInfoFromCommitSHA("HEAD", ...) resolves correctly in worktree
• Updated TODO.md marking all items in the worktree fix slice as complete

Impact

Users can now use gitview operations from git worktree paths without errors when resolving HEAD references.

[claude]

Claude finished @meekrosoft's task in 1m 27s —— View job

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PR Review: Fix HEAD resolution in git worktrees

• Run static analysis (build, vet, mod tidy)
• Review changed files
• Post review feedback

Static Analysis

All checks pass: go build, go vet, and go mod tidy report no issues.

Review

This is a clean, well-scoped fix. The change is minimal (swapping PlainOpen → PlainOpenWithOptions with EnableDotGitCommonDir: true) and directly addresses the problem. The test is thorough — it validates New(), BranchName(), and GetCommitInfoFromCommitSHA("HEAD", ...) all work from a worktree context.

A few observations:

Code change — No concerns. EnableDotGitCommonDir: true is the correct go-git option for worktree support, and it's backward-compatible (regular repos work the same way).

Test quality — Good coverage of the three key operations. The test creates a real git worktree via exec.Command, which is the right approach for testing this behavior. Cleanup is handled by AfterTest() removing the entire tmpDir, which covers both the main repo and worktree directories.

TODO.md — Follows the repo's slice tracking convention correctly.

No issues found. This is a solid single-slice fix — small, focused, well-tested. LGTM. 👍