React Native (Expo) mobile app + full game flow

Brought Ki Clash to mobile with a React Native (Expo) app, then ported the full game flow and game-feel features across.

What changed

• Scaffold — Set up the Expo project with TypeScript and expo-router (file-based routing: app/index.tsx, app/game.tsx, app/pvp.tsx), plus a shared lib for API access (src/lib/api.ts) and theming (src/lib/theme.ts). (commit 3c8ca45)
• Game UI components — Added the mobile component set to render the match natively: ActionCard, GameBoard, KiMeter, MatchHUD, TurnReveal. (commit 821c6d2)
• Game flow — Implemented the full flow with two driving hooks: useGame (AI matches) and usePvP (player-vs-player), wired into the game and pvp screens. (commit 9fa0bb1)
• Mobile polish — Added a useAppState hook for foreground/background transitions, SafeAreaProvider in the root layout, and environment configuration via .env.example. (commit 255ae8c)
• Game feel — Ported the web game-feel features to native: AIThinking, Countdown, and MuteButton components, sound effects via useSoundEffects, plus updates to MatchHUD, TurnReveal, and useGame to match. (commit 8b6095b)

Commits

• 3c8ca45 — feat: set up React Native (Expo) project with TypeScript and expo-router
• 821c6d2 — feat: add mobile game UI components for React Native
• 9fa0bb1 — feat: implement mobile game flow with AI and PvP hooks
• 255ae8c — feat: add mobile polish — AppState handler, SafeAreaProvider, env config
• 8b6095b — feat: port all game feel features to React Native mobile