- Replace Bold/Dim attributes with explicit colors that survive light
themes (Reverse instead of hardcoded black/white for cursor/selection).
- Only redraw cells that actually changed each frame instead of a full
clear, and center the field within the live viewport.
- Add orca-c's ruler-snapped grid resize keys (( ) _ +) and its fancy
ruler-frame corners, ported from tui_main.c.
- Add ~/.config/orca-rs/config.toml for a default MIDI port name.
