feat(mobile): add Expo React Native app

frontend/.gitignore

@@ -0,0 +1,41 @@
+# Learn more https://docs.github.com/en/get-started/getting-started-with-git/ignoring-files
+
+# dependencies
+node_modules/
+
+# Expo
+.expo/
+dist/
+web-build/
+expo-env.d.ts
+
+# Native
+.kotlin/
+*.orig.*
+*.jks
+*.p8
+*.p12
+*.key
+*.mobileprovision
+
+# Metro
+.metro-health-check*
+
+# debug
+npm-debug.*
+yarn-debug.*
+yarn-error.*
+
+# macOS
+.DS_Store
+*.pem
+
+# local env files
+.env*.local
+
+# typescript
+*.tsbuildinfo
+
+# generated native folders
+/ios
+/android

frontend/.prettierignore

@@ -0,0 +1,6 @@
+node_modules/
+.expo/
+dist/
+web-build/
+package-lock.json
+assets/

frontend/.prettierrc

@@ -0,0 +1,7 @@
+{
+  "printWidth": 100,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "semi": true,
+  "tabWidth": 2
+}

frontend/App.tsx

@@ -0,0 +1,5 @@
+import { HomeScreen } from './src/screens/HomeScreen';
+
+export default function App() {
+  return <HomeScreen />;
+}

frontend/app.json

@@ -0,0 +1,22 @@
+{
+  "expo": {
+    "name": "Timeflow",
+    "slug": "timeflow",
+    "version": "1.0.0",
+    "orientation": "portrait",
+    "icon": "./assets/icon.png",
+    "userInterfaceStyle": "light",
+    "ios": {
+      "supportsTablet": true
+    },
+    "android": {
+      "adaptiveIcon": {
+        "backgroundColor": "#E6F4FE",
+        "foregroundImage": "./assets/android-icon-foreground.png",
+        "backgroundImage": "./assets/android-icon-background.png",
+        "monochromeImage": "./assets/android-icon-monochrome.png"
+      },
+      "predictiveBackGestureEnabled": false
+    }
+  }
+}

frontend/eslint.config.js

@@ -0,0 +1,18 @@
+// ESLint flat config，基于 Expo 官方规则集
+// 文档: https://docs.expo.dev/guides/using-eslint/
+const { defineConfig } = require('eslint/config');
+const expoConfig = require('eslint-config-expo/flat');
+const prettierConfig = require('eslint-config-prettier');
+
+module.exports = defineConfig([
+  expoConfig,
+  prettierConfig,
+  {
+    ignores: ['dist/**', '.expo/**', 'web-build/**', 'node_modules/**'],
+  },
+  {
+    rules: {
+      'no-console': ['warn', { allow: ['warn', 'error'] }],
+    },
+  },
+]);

frontend/index.ts

@@ -0,0 +1,8 @@
+import { registerRootComponent } from 'expo';
+
+import App from './App';
+
+// registerRootComponent calls AppRegistry.registerComponent('main', () => App);
+// It also ensures that whether you load the app in Expo Go or in a native build,
+// the environment is set up appropriately
+registerRootComponent(App);