Add a "Stash count" indicator to the status panel

[Divyam-Chauhan]

What to do: Show how many stashes exist (e.g., Stashes: 3) in the Repository Status panel. Many developers forget about stashed work.

Files: git_parser.py, ui.py

• Add a method: def get_stash_count(self) -> int: using len(self.repo.git.stash("list").splitlines()) (returns 0 if empty)
• Add a line in _render_top_left() to display it

Why beginner-friendly: One tiny method + one UI line. Same pattern as staged/unstaged/untracked.