diff lines without a sign char were misaligned.
Replace mixed `⎿` and `L` prefixes with `└` in TUI rendering. <img width="454" height="659" alt="Screenshot 2025-08-13 at 4 02 03 PM" src="https://github.com/user-attachments/assets/61c9c7da-830b-4040-bb79-a91be90870ca" />
Show the diff for apply patch <img width="801" height="345" alt="image" src="https://github.com/user-attachments/assets/a15d6112-e83e-4612-a2bd-43285689a358" /> Stack: -> #2050 #2049