Refactor mobile to fix dependency resolution and add polyfills

Update Expo and React dependencies to compatible versions. Create a
custom Metro config to resolve module conflicts in the workspace and
map Jest modules to local node_modules.

Add a SharedArrayBuffer polyfill for older runtimes and introduce an
adapter for expo-notifications to abstract direct imports.

apps/mobile/jest.config.cjs

@@ -1,4 +1,12 @@
 module.exports = {
   preset: 'jest-expo',
   testMatch: ['**/__tests__/**/*.test.[jt]s?(x)'],
+  moduleNameMapper: {
+    '^react$': '<rootDir>/node_modules/react',
+    '^react-test-renderer$': '<rootDir>/node_modules/react-test-renderer',
+    '^react-native-safe-area-context$': '<rootDir>/node_modules/react-native-safe-area-context',
+    '^react-native-screens$': '<rootDir>/node_modules/react-native-screens',
+    '^@react-native-async-storage/async-storage$':
+      '<rootDir>/node_modules/@react-native-async-storage/async-storage',
+  },
 };