Task: Fix Tmux Border Display Issues (ASCII characters instead of Unicode lines)

Task: Fix Tmux Border Display Issues (ASCII characters instead of Unicode lines): a task in Terminal-Lego-15k (Harbor dataset). When using tmux , window borders sometimes display as ASCII characters ( x , q , l , k , m , j ) instead of proper Unicode line-drawing characters ( │ , ─ , ┌ , ┐ , └ , ┘…