feat(nutrition): 优化营养成分表分析功能并移除流式显示

- 移除流式分析文本显示，简化用户界面
- 修复ImagePicker媒体类型配置，使用数组格式
- 简化API响应处理逻辑，直接使用服务端返回数据
- 移除旧格式转换函数，统一使用新的API响应格式
- 清理冗余状态变量和UI组件，提升代码可维护性

app/food/nutrition-label-analysis.tsx

@@ -5,10 +5,7 @@ import { useSafeAreaTop } from '@/hooks/useSafeAreaWithPadding';
 import {
   analyzeNutritionImage,
   analyzeNutritionLabelStream,
-  convertNewApiResultToOldFormat,
-  type NutritionAnalysisResponse,
-  type NutritionItem,
-  type NutritionLabelAnalysisResult
+  type NutritionAnalysisResponse
 } from '@/services/nutritionLabelAnalysis';
 import { triggerLightHaptic } from '@/utils/haptics';
 import { Ionicons } from '@expo/vector-icons';
@@ -40,8 +37,6 @@ export default function NutritionLabelAnalysisScreen() {
   const [imageUri, setImageUri] = useState<string | null>(null);
   const [isAnalyzing, setIsAnalyzing] = useState(false);
   const [showImagePreview, setShowImagePreview] = useState(false);
-  const [analysisText, setAnalysisText] = useState<string>('');
-  const [analysisResult, setAnalysisResult] = useState<NutritionLabelAnalysisResult | null>(null);
   const [newAnalysisResult, setNewAnalysisResult] = useState<NutritionAnalysisResponse | null>(null);
   const [isUploading, setIsUploading] = useState(false);
 
@@ -94,7 +89,7 @@ export default function NutritionLabelAnalysisScreen() {
     triggerLightHaptic();
 
     const result = await ImagePicker.launchCameraAsync({
-      mediaTypes: ImagePicker.MediaTypeOptions.Images,
+      mediaTypes: ['images'],
       allowsEditing: true,
       aspect: [4, 3],
       quality: 0.8,
@@ -102,9 +97,7 @@ export default function NutritionLabelAnalysisScreen() {
 
     if (!result.canceled && result.assets[0]) {
       setImageUri(result.assets[0].uri);
-      setAnalysisText(''); // 清除之前的分析文本
-      setAnalysisResult(null); // 清除之前的分析结果
-      setNewAnalysisResult(null); // 清除新的分析结果
+      setNewAnalysisResult(null); // 清除之前的分析结果
     }
   };
 
@@ -113,7 +106,7 @@ export default function NutritionLabelAnalysisScreen() {
     triggerLightHaptic();
 
     const result = await ImagePicker.launchImageLibraryAsync({
-      mediaTypes: ImagePicker.MediaTypeOptions.Images,
+      mediaTypes: ['images'],
       allowsEditing: true,
       aspect: [4, 3],
       quality: 0.8,
@@ -121,9 +114,7 @@ export default function NutritionLabelAnalysisScreen() {
 
     if (!result.canceled && result.assets[0]) {
       setImageUri(result.assets[0].uri);
-      setAnalysisText(''); // 清除之前的分析文本
-      setAnalysisResult(null); // 清除之前的分析结果
-      setNewAnalysisResult(null); // 清除新的分析结果
+      setNewAnalysisResult(null); // 清除之前的分析结果
     }
   };
 
@@ -140,7 +131,6 @@ export default function NutritionLabelAnalysisScreen() {
 
       // 清理状态
       setIsAnalyzing(false);
-      setAnalysisText('');
 
       // 触觉反馈
       triggerLightHaptic();
@@ -154,8 +144,6 @@ export default function NutritionLabelAnalysisScreen() {
     if (isAnalyzing) return;
 
     setIsAnalyzing(true);
-    setAnalysisText('');
-    setAnalysisResult(null);
 
     // 延迟滚动到分析结果区域，给UI一些时间更新
     setTimeout(() => {
@@ -169,17 +157,8 @@ export default function NutritionLabelAnalysisScreen() {
         { imageUri: uri },
         {
           onChunk: (chunk: string) => {
-            setAnalysisText(prev => {
-              const newText = prev + chunk;
-              // 在接收到第一个文本块时滚动到分析结果区域
-              if (isFirstChunk && newText.length > 0) {
-                isFirstChunk = false;
-                setTimeout(() => {
-                  scrollViewRef.current?.scrollToEnd({ animated: true });
-                }, 100);
-              }
-              return newText;
-            });
+            // 流式分析暂时保留，但不再显示文本
+            console.log('[NUTRITION_ANALYSIS] Stream chunk:', chunk);
           },
           onEnd: () => {
             setIsAnalyzing(false);
@@ -189,7 +168,6 @@ export default function NutritionLabelAnalysisScreen() {
           onError: (error: any) => {
             console.error('[NUTRITION_ANALYSIS] Analysis failed:', error);
             setIsAnalyzing(false);
-            setAnalysisText('');
             streamAbortRef.current = null;
 
             // 如果是用户主动取消，不显示错误提示
@@ -202,7 +180,6 @@ export default function NutritionLabelAnalysisScreen() {
     } catch (error) {
       console.error('[NUTRITION_ANALYSIS] Analysis error:', error);
       setIsAnalyzing(false);
-      setAnalysisText('');
       Alert.alert('分析失败', '无法识别成分表，请尝试拍摄更清晰的照片');
     }
   }, [isAnalyzing]);
@@ -212,8 +189,6 @@ export default function NutritionLabelAnalysisScreen() {
     if (isAnalyzing || isUploading) return;
 
     setIsUploading(true);
-    setAnalysisText('');
-    setAnalysisResult(null);
     setNewAnalysisResult(null);
 
     // 延迟滚动到分析结果区域，给UI一些时间更新
@@ -239,21 +214,8 @@ export default function NutritionLabelAnalysisScreen() {
       console.log('[NUTRITION_ANALYSIS] API响应:', analysisResponse);
 
       if (analysisResponse.success && analysisResponse.data) {
-        // 转换为旧格式以便与现有UI兼容
-        const oldFormatResult = convertNewApiResultToOldFormat(analysisResponse, uploadResult.url);
-
-        if (oldFormatResult) {
-          setAnalysisResult(oldFormatResult);
-          setNewAnalysisResult(analysisResponse);
-
-          // 生成分析文本
-          const analysisText = analysisResponse.data
-            .map((item: NutritionItem) => `**${item.name}**: ${item.value}\n${item.analysis}`)
-            .join('\n\n');
-          setAnalysisText(analysisText);
-        } else {
-          throw new Error('无法解析API返回结果');
-        }
+        // 直接使用服务端返回的数据，不做任何转换
+        setNewAnalysisResult(analysisResponse);
       } else {
         throw new Error(analysisResponse.message || '分析失败');
       }
@@ -261,7 +223,6 @@ export default function NutritionLabelAnalysisScreen() {
       console.error('[NUTRITION_ANALYSIS] 新API分析失败:', error);
       setIsUploading(false);
       setIsAnalyzing(false);
-      setAnalysisText('');
 
       // 显示错误提示
       Alert.alert(
@@ -318,7 +279,7 @@ export default function NutritionLabelAnalysisScreen() {
               </TouchableOpacity>
 
               {/* 开始分析按钮 */}
-              {!isAnalyzing && !isUploading && !analysisText && (
+              {!isAnalyzing && !isUploading && !newAnalysisResult && (
                 <TouchableOpacity
                   style={styles.analyzeButton}
                   onPress={() => startNewAnalysis(imageUri)}
@@ -334,8 +295,6 @@ export default function NutritionLabelAnalysisScreen() {
                 style={styles.deleteImageButton}
                 onPress={() => {
                   setImageUri(null);
-                  setAnalysisText('');
-                  setAnalysisResult(null);
                   setNewAnalysisResult(null);
                   triggerLightHaptic();
                 }}
@@ -373,31 +332,6 @@ export default function NutritionLabelAnalysisScreen() {
           )}
         </View>
 
-        {/* 流式分析文本区域 */}
-        {analysisText && (
-          <View style={styles.analysisTextCard}>
-            <View style={styles.analysisTextHeader}>
-              <Text style={styles.analysisTextTitle}>分析结果</Text>
-              {isAnalyzing && (
-                <TouchableOpacity
-                  style={styles.cancelAnalysisButton}
-                  onPress={cancelAnalysis}
-                  activeOpacity={0.8}
-                >
-                  <Ionicons name="close-outline" size={16} color="#FF4444" />
-                  <Text style={styles.cancelAnalysisText}>停止</Text>
-                </TouchableOpacity>
-              )}
-            </View>
-            <Text style={styles.analysisTextContent}>{analysisText}</Text>
-            {isAnalyzing && (
-              <View style={styles.streamingIndicator}>
-                <ActivityIndicator size="small" color={Colors.light.primary} />
-                <Text style={styles.streamingText}>正在分析中...</Text>
-              </View>
-            )}
-          </View>
-        )}
 
         {/* 新API营养成分详细分析结果 */}
         {newAnalysisResult && newAnalysisResult.success && newAnalysisResult.data && (
@@ -428,7 +362,7 @@ export default function NutritionLabelAnalysisScreen() {
         )}
 
         {/* 加载状态 */}
-        {isAnalyzing && !analysisText && !isUploading && (
+        {isAnalyzing && !newAnalysisResult && !isUploading && (
           <View style={styles.loadingContainer}>
             <ActivityIndicator size="large" color={Colors.light.primary} />
             <Text style={styles.loadingText}>正在分析成分表...</Text>
@@ -725,66 +659,6 @@ const styles = StyleSheet.create({
     fontWeight: '600',
     marginLeft: 6,
   },
-  // 分析文本卡片样式
-  analysisTextCard: {
-    backgroundColor: Colors.light.background,
-    margin: 16,
-    borderRadius: 16,
-    padding: 20,
-    shadowColor: '#000',
-    shadowOffset: {
-      width: 0,
-      height: 2,
-    },
-    shadowOpacity: 0.1,
-    shadowRadius: 4,
-    elevation: 3,
-  },
-  analysisTextHeader: {
-    flexDirection: 'row',
-    justifyContent: 'space-between',
-    alignItems: 'center',
-    marginBottom: 16,
-  },
-  analysisTextTitle: {
-    fontSize: 18,
-    fontWeight: '600',
-    color: Colors.light.text,
-  },
-  cancelAnalysisButton: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    gap: 4,
-    paddingHorizontal: 8,
-    paddingVertical: 4,
-    borderRadius: 12,
-    backgroundColor: 'rgba(255,68,68,0.1)',
-    borderWidth: 1,
-    borderColor: 'rgba(255,68,68,0.3)',
-  },
-  cancelAnalysisText: {
-    fontSize: 12,
-    fontWeight: '600',
-    color: '#FF4444',
-  },
-  analysisTextContent: {
-    fontSize: 15,
-    lineHeight: 22,
-    color: Colors.light.text,
-    marginBottom: 12,
-  },
-  streamingIndicator: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    justifyContent: 'center',
-    gap: 8,
-    paddingVertical: 8,
-  },
-  streamingText: {
-    fontSize: 14,
-    color: Colors.light.textSecondary,
-    fontStyle: 'italic',
-  },
   // 营养成分详细分析卡片样式
   nutritionDetailsCard: {
     backgroundColor: Colors.light.background,