feat: add mobile application structure with emotion picker and API integration

- Added favicon and icon assets for the mobile app.
- Implemented EmotionPicker component for selecting emotions with child options.
- Created hooks for fetching emotions, feeds, and rapport data.
- Established API service for handling requests and authentication.
- Integrated Zustand for state management of user authentication.
- Defined color palette for the application.
- Set up TypeScript types for various entities including User, Emotion, and Feed.
- Configured Babel and TypeScript for the mobile project.
- Added package.json with necessary dependencies for Expo and React Native.

frontend/src/lib/auth-store.ts

@@ -38,7 +38,7 @@ interface AuthState {
 
 export const useAuthStore = create<AuthState>()(
   persist(
-    (set, get) => ({
+    (set) => ({
       user: null,
       token: null,
       isAuthenticated: false,