Panel now selects from four width tiers based on $COLUMNS (with a 6-col
buffer per side before stepping up): 52-wide (default), 70, 74, or 78.
Each tier carries richer category descriptions sized to fit the layout.
The box is horizontally centered on every draw via a left-padding prefix.
Key reader switches from stty min 1 to min 0 / time 3, giving a 0.3 s
poll interval so COLUMNS changes are detected without a keypress. The
erase formula is now wrap-aware: prev_max_line_width / COLUMNS gives the
wrap factor, ensuring old wider panels are fully cleared after narrowing.
Idle timeout ticks that detect no resize are skipped entirely.
rootiest
