Terminals can't scale glyphs, so the banner now picks a layout per
column width instead of always rendering the full 101-col logo:
- Wide (>= logo width): full ASCII logo + tagline.
- Mid (>= 58 cols): centered rule banner that expands with viewport.
- Narrow (>= 34 cols): brand line + tagline, both width-aware.
- < 34 cols: hidden.
SessionPanel surfaces model/cwd/sid inline when the hero column is
hidden, so narrow layouts don't lose that info. Logo width constants
derive from the art itself.
This PR groups the TUI fixes that restore macOS Terminal usability and clean up the theme/composer regressions:
- copy transcript selections on macOS drag-release so Terminal.app users can copy while mouse tracking is enabled
- copy composer selections on macOS drag-release; composer selection is internal to TextInput and does not use the global Ink selection bus
- keep IDE Cmd+C forwarding setup macOS-only, and make keybinding conflict checks respect simple when-clause overlap/negation
- force truecolor before chalk initializes (unless NO_COLOR / FORCE_COLOR / HERMES_TUI_TRUECOLOR opt-outs apply) so the default banner keeps its gold/amber/bronze gradient in Terminal.app
- move TUI surfaces onto semantic theme tokens and preserve skin prompt symbols as bare tokens with renderer-owned spacing
- render focused placeholders as dim hint text in TTY mode instead of inverse/selected-looking synthetic cursor text