bento home: redesigned home, track detail, playground gallery, uikit nav

Created by: jedmund

Summary

Rebuilds the home screen around the handoff's bento design and the supporting navigation machinery underneath it.

• Bento home replaces the tree-expanding HomeScreen. New chips (streak, module, style), a continue-learning hero card with five animated hero medias (spectrum, waveform, harmonics, piano roll, arrangement), an up-next reco card, per-track tiles with progress strips, and a playground rail of pill cards.
• Push destinations for deeper navigation: TrackDetailScreen (full curriculum listing with inline lesson rows + per-status circles) and PlaygroundGalleryScreen (the "See all" target showing every tool grouped into Instruments / Explorers / Exercises with blurbs and a "coming soon" badge for unfinished ones).
• Design system: centralizes Typography, ColorTokens, and TrackPalette tokens plus a debug DesignSystemGallery view. Foreground tokens are ShapeStyle values that pick up the user's filter palette as a subtle hue tint.
• Routing: CurriculumStore switches from a single NavigationState enum to a [Route] path. Adds PlaygroundCatalog as the single source of tool classification + ready/coming-soon status.
• UIKit NavigationHost: UIViewControllerRepresentable wrapping a UINavigationController with a custom slide-with-fade transition animator and a UIPercentDrivenInteractiveTransition-driven edge-pan. Gives us real interactive-pop physics while keeping the GenerativeBackground persistent behind every pushed screen (previous NavigationStack approach caused ghosting with transparent hosting controllers).
• Dark mode: filter palette auto-inverts from the user's light pick; foreground tokens still resolve to near-white with a subtle hue shift.
• Legacy HomeScreen, TrackScreen, ModuleScreen, and PlaygroundGrid retired.

Test plan

• Home renders over the filter wallpaper (light + dark)
• Tap a track tile: track detail pushes, filter stays constant, no ghosting
• Tap a lesson row: pushes into LessonScreen
• Back chip + edge-swipe both pop with proper physics
• Tap "See all" in Playground header: gallery pushes
• Gallery coming-soon cards are faded and non-tappable
• Style chip on home opens the background diagnostics panel
• Debug toolbar (DEBUG only): hero media switcher, lesson picker, design system gallery all work
• Filter darkColor changes visibly tint text (warmer / cooler)