feat: improve prowl list output with colored, hierarchical formatting
Reorganize the text output to group by worktree with indented tabs and
panes. Add Rainbow dependency for terminal colors with --no-color flag
support. Worktree headers show project name extracted from path, tab/pane
rows include numbered labels, and focused pane is highlighted in green.
Redundant cwd display is suppressed when it matches the worktree path.