Import beads' UX design system into gastown:
- Add internal/ui/ package with Ayu theme colors and semantic styling
- styles.go: AdaptiveColor definitions for light/dark mode
- terminal.go: TTY detection, NO_COLOR/CLICOLOR support
- markdown.go: Glamour rendering with agent mode bypass
- pager.go: Smart paging with GT_PAGER support
- Add colorized help output (internal/cmd/help.go)
- Group headers in accent color
- Command names styled for scannability
- Flag types and defaults muted
- Add gt thanks command (internal/cmd/thanks.go)
- Contributor display with same logic as bd thanks
- Styled with Ayu theme colors
- Update gt doctor to match bd doctor UX
- Category grouping (Core, Infrastructure, Rig, Patrol, etc.)
- Semantic icons (✓ ⚠ ✖) with Ayu colors
- Tree connectors for detail lines
- Summary line with pass/warn/fail counts
- Warnings section at end with numbered issues
- Migrate existing styles to use ui package
- internal/style/style.go uses ui.ColorPass etc.
- internal/tui/feed/styles.go uses ui package colors
Co-Authored-By: SageOx <ox@sageox.ai>
e1f2bb8b4b