Initial commit: WalletTracker app with Firebase integration

- Setup Expo project with TypeScript
- Implement authentication (Login/Signup/Logout)
- Create Dashboard, Transactions, Subscriptions, and Analysis screens
- Add Firebase services (Auth, Firestore, Storage)
- Implement real-time synchronization
- Add charts and analytics
- Create reusable components (Button, InputText, TransactionCard, SubscriptionCard)
- Configure React Navigation with bottom tabs
- Add Firestore security rules
- Create comprehensive documentation (README, FIREBASE_SETUP, TESTING)

src/navigation/AppNavigator.tsx

@@ -0,0 +1,117 @@
+import React from 'react';
+import { NavigationContainer } from '@react-navigation/native';
+import { createStackNavigator } from '@react-navigation/stack';
+import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';
+import { ActivityIndicator, View, StyleSheet } from 'react-native';
+
+import { useAuth } from '../hooks/useAuth';
+import { LoginScreen } from '../screens/LoginScreen';
+import { SignupScreen } from '../screens/SignupScreen';
+import { DashboardScreen } from '../screens/DashboardScreen';
+import { TransactionScreen } from '../screens/TransactionScreen';
+import { SubscriptionScreen } from '../screens/SubscriptionScreen';
+import { AnalysisScreen } from '../screens/AnalysisScreen';
+
+import { RootStackParamList, MainTabParamList } from '../types';
+
+const Stack = createStackNavigator<RootStackParamList>();
+const Tab = createBottomTabNavigator<MainTabParamList>();
+
+const MainTabs = () => {
+  return (
+    <Tab.Navigator
+      screenOptions={{
+        headerShown: false,
+        tabBarActiveTintColor: '#4A90E2',
+        tabBarInactiveTintColor: '#999',
+        tabBarStyle: {
+          backgroundColor: '#FFF',
+          borderTopWidth: 1,
+          borderTopColor: '#E0E0E0',
+          paddingBottom: 8,
+          paddingTop: 8,
+          height: 60
+        },
+        tabBarLabelStyle: {
+          fontSize: 12,
+          fontWeight: '600'
+        }
+      }}
+    >
+      <Tab.Screen
+        name="Dashboard"
+        component={DashboardScreen}
+        options={{
+          tabBarLabel: 'Tableau de bord',
+          tabBarIcon: ({ color }) => <TabIcon icon="📊" color={color} />
+        }}
+      />
+      <Tab.Screen
+        name="Transactions"
+        component={TransactionScreen}
+        options={{
+          tabBarLabel: 'Transactions',
+          tabBarIcon: ({ color }) => <TabIcon icon="💸" color={color} />
+        }}
+      />
+      <Tab.Screen
+        name="Subscriptions"
+        component={SubscriptionScreen}
+        options={{
+          tabBarLabel: 'Abonnements',
+          tabBarIcon: ({ color }) => <TabIcon icon="📱" color={color} />
+        }}
+      />
+      <Tab.Screen
+        name="Analysis"
+        component={AnalysisScreen}
+        options={{
+          tabBarLabel: 'Analyses',
+          tabBarIcon: ({ color }) => <TabIcon icon="📈" color={color} />
+        }}
+      />
+    </Tab.Navigator>
+  );
+};
+
+const TabIcon = ({ icon, color }: { icon: string; color: string }) => (
+  <View style={{ opacity: color === '#4A90E2' ? 1 : 0.5 }}>
+    <View>{icon}</View>
+  </View>
+);
+
+export const AppNavigator = () => {
+  const { user, initializing } = useAuth();
+
+  if (initializing) {
+    return (
+      <View style={styles.loadingContainer}>
+        <ActivityIndicator size="large" color="#4A90E2" />
+      </View>
+    );
+  }
+
+  return (
+    <NavigationContainer>
+      <Stack.Navigator screenOptions={{ headerShown: false }}>
+        {user ? (
+          <Stack.Screen name="Main" component={MainTabs} />
+        ) : (
+          <>
+            <Stack.Screen name="Login" component={LoginScreen} />
+            <Stack.Screen name="Signup" component={SignupScreen} />
+          </>
+        )}
+      </Stack.Navigator>
+    </NavigationContainer>
+  );
+};
+
+const styles = StyleSheet.create({
+  loadingContainer: {
+    flex: 1,
+    justifyContent: 'center',
+    alignItems: 'center',
+    backgroundColor: '#F8F9FA'
+  }
+});