feat: Implement Food Camera Screen and Floating Food Overlay

- Added FoodCameraScreen for capturing food images with camera functionality.
- Integrated image picker for selecting images from the gallery.
- Created FloatingFoodOverlay for quick access to food library and scanning options.
- Updated NutritionRadarCard to utilize FloatingFoodOverlay for adding food.
- Enhanced ExploreScreen layout and styles for better user experience.
- Removed unused SafeAreaView from ExploreScreen.
- Updated profile edit screen to remove unnecessary state variables.
- Updated avatar image source in profile edit screen.
- Added ExpoCamera dependency for camera functionalities.

components/FloatingFoodOverlay.tsx

@@ -0,0 +1,192 @@
+import { ROUTES } from '@/constants/Routes';
+import { Ionicons } from '@expo/vector-icons';
+import { BlurView } from 'expo-blur';
+import { useRouter } from 'expo-router';
+import React from 'react';
+import {
+  Modal,
+  StyleSheet,
+  Text,
+  TouchableOpacity,
+  View,
+} from 'react-native';
+
+interface FloatingFoodOverlayProps {
+  visible: boolean;
+  onClose: () => void;
+  mealType?: string;
+}
+
+export function FloatingFoodOverlay({ visible, onClose, mealType = 'dinner' }: FloatingFoodOverlayProps) {
+  const router = useRouter();
+
+  const handleFoodLibrary = () => {
+    onClose();
+    router.push(`${ROUTES.FOOD_LIBRARY}?mealType=${mealType}`);
+  };
+
+  const handlePhotoRecognition = () => {
+    onClose();
+    router.push(`/food-camera?mealType=${mealType}`);
+  };
+
+  const menuItems = [
+    {
+      id: 'scan',
+      title: '扫描',
+      icon: '📷',
+      backgroundColor: '#4FC3F7',
+      onPress: handlePhotoRecognition,
+    },
+    {
+      id: 'food-library',
+      title: '食物库',
+      icon: '🍎',
+      backgroundColor: '#FF9500',
+      onPress: handleFoodLibrary,
+    },
+  ];
+
+  return (
+    <Modal
+      visible={visible}
+
+      transparent={true}
+      animationType="fade"
+      onRequestClose={onClose}
+
+    >
+      <View style={styles.overlay}>
+        <TouchableOpacity
+          style={styles.backdrop}
+          activeOpacity={1}
+          onPress={onClose}
+        />
+
+        <View style={styles.container}>
+          <BlurView intensity={80} tint="light" style={styles.blurContainer}>
+            <View style={styles.header}>
+              <Text style={styles.title}>日常记录</Text>
+            </View>
+
+            <View style={styles.menuGrid}>
+              {menuItems.map((item) => (
+                <TouchableOpacity
+                  key={item.id}
+                  style={styles.menuItem}
+                  onPress={item.onPress}
+                  activeOpacity={0.7}
+                >
+                  <View style={[styles.iconContainer, { backgroundColor: item.backgroundColor }]}>
+                    <Text style={styles.iconText}>{item.icon}</Text>
+                  </View>
+                  <Text style={styles.menuText}>{item.title}</Text>
+                </TouchableOpacity>
+              ))}
+            </View>
+          </BlurView>
+
+          <TouchableOpacity
+            style={styles.closeButton}
+            onPress={onClose}
+            activeOpacity={0.7}
+          >
+            <View style={styles.closeButtonInner}>
+              <Ionicons name="close" size={24} color="#666" />
+            </View>
+          </TouchableOpacity>
+        </View>
+      </View>
+    </Modal>
+  );
+}
+
+const styles = StyleSheet.create({
+  overlay: {
+    flex: 1,
+    backgroundColor: 'rgba(0, 0, 0, 0.4)',
+    justifyContent: 'center',
+    alignItems: 'center',
+  },
+  backdrop: {
+    position: 'absolute',
+    top: 0,
+    left: 0,
+    right: 0,
+    bottom: 0,
+  },
+  container: {
+    alignItems: 'center',
+  },
+  blurContainer: {
+    borderRadius: 20,
+    overflow: 'hidden',
+    backgroundColor: 'rgba(255, 255, 255, 0.95)',
+    minWidth: 340,
+    paddingVertical: 20,
+    paddingHorizontal: 16,
+    minHeight: 100
+  },
+  header: {
+    paddingBottom: 20,
+    alignItems: 'center',
+  },
+  title: {
+    fontSize: 16,
+    fontWeight: '600',
+    color: '#333',
+  },
+  menuGrid: {
+    flexDirection: 'row',
+    justifyContent: 'space-around',
+    gap: 32,
+  },
+  menuItem: {
+    alignItems: 'center',
+    flex: 1,
+  },
+  iconContainer: {
+    width: 48,
+    height: 48,
+    borderRadius: 24,
+    alignItems: 'center',
+    justifyContent: 'center',
+    marginBottom: 8,
+    shadowColor: '#000',
+    shadowOffset: {
+      width: 0,
+      height: 2,
+    },
+    shadowOpacity: 0.15,
+    shadowRadius: 4,
+    elevation: 4,
+  },
+  iconText: {
+    fontSize: 22,
+  },
+  menuText: {
+    fontSize: 13,
+    fontWeight: '500',
+    color: '#333',
+    textAlign: 'center',
+  },
+  closeButton: {
+    marginTop: 20,
+  },
+  closeButtonInner: {
+    width: 44,
+    height: 44,
+    borderRadius: 22,
+    backgroundColor: 'rgba(255, 255, 255, 0.9)',
+    alignItems: 'center',
+    justifyContent: 'center',
+    shadowColor: '#000',
+    shadowOffset: {
+      width: 0,
+      height: 2,
+    },
+    shadowOpacity: 0.1,
+    shadowRadius: 4,
+    elevation: 3,
+  },
+});