Allow /plannotator-review <path> to review a specific worktree #896

Summary

Allow /plannotator-review to accept a local path and use it as the review workspace/cwd.

Example:

/plannotator-review .worktrees/my-feature
/plannotator-review /absolute/path/to/repo/.worktrees/my-feature

Motivation

When working with agent-created git worktrees, the active chat/session cwd may be the main checkout while the implementation lives in a separate worktree. Today /plannotator-review opens review for the current session cwd, and passing a worktree path as a positional argument is ignored unless it is a URL.

This makes it awkward to review the correct worktree without starting a new agent/session from that worktree directory.

Current behavior

The slash command supports PR URLs and flags such as --git, --local, and --no-local, but local non-URL positional args are not treated as a cwd/workspace target.

Requested behavior

If the first positional argument is a local path, resolve it relative to the current cwd and pass it as the code review cwd.

Suggested behavior:

• /plannotator-review <path> reviews that local path/worktree.
• Existing /plannotator-review <PR URL> behavior remains unchanged.
• Existing flags continue to work, e.g. /plannotator-review .worktrees/my-feature --git.
• Show a clear error if the path does not exist or is not a git/JJ workspace.

Notes

The shared event API already supports code-review with a cwd payload, so this request is specifically about exposing that capability through the user-facing slash command.

Related issues:

• code review doesn't work when using worktrees #196 covered worktree support generally.
• [FEATURE] submit_review tool for Opencode extension #295 asks for review triggering beyond the single manual slash command.
• Bug: untracked files missing from code review when agent CWD is a subdirectory #449 covers cwd/subdirectory behavior in code review.