v0.5.0

Changelog

• f100344: Add help overlay, NO_COLOR support, and non-TTY guard, Make help overlay fit terminal height with scrolling (@s-johri)
• 59baa10: Clamp help scroll to true max so scroll-up responds at the bottom (@s-johri)
• 1cc4bdc: Add adaptive two-column layout for wide terminals with row truncation (@s-johri)
• c865fc7: Styling / polish pass + opt-in motion system (@s-johri)
• 7a9b38e: Add runtime themes with presets and live in-app switcher (@s-johri)
• f503de5: Mark v0.5.0 complete; note M41 adaptive-layout reversal (@s-johri)