Upgrade to Expo SDK 56

[ph33nx]

Upgrades the dreams starter to Expo SDK 56, fixes the typecheck, and adds a CI gate. Mirrors the validated recipe already merged on astrology-starter-app.

Changes

• Bumped expo to 56 with aligned react-native (0.85.3), react/react-dom (19.2.3), and the rest of the expo package set via expo install --fix.
• Aligned devDeps: babel-preset-expo ~56.0.0, jest-expo ~56.0.5, typescript ~6.0.3, @types/react ~19.2.14.
• Config migration in both app.json and app.config.ts: removed newArchEnabled (new arch is default in SDK 56) and android.edgeToEdgeEnabled (dropped in SDK 56); moved the splash block into the expo-splash-screen plugin (added expo-splash-screen dependency).
• tsconfig: added exclude for node_modules, dist, and test files.
• nativewind-env.d.ts: added declare module "*.css" so the global.css import typechecks.
• Added .github/workflows/ci.yml running npm ci, tsc --noEmit, and npm test.

Verification

• npx expo-doctor: 21/21 checks passed, no issues.
• npx tsc --noEmit: 0 errors.
• npm test: 10/10 tests pass.