feat(medications): 添加AI用药分析功能

- 集成流式AI分析接口，支持实时展示分析结果
- 添加VIP权限校验和会员弹窗引导
- 使用Markdown渲染AI分析内容
- 优化底部按钮布局，AI分析按钮占2/3宽度
- 支持请求取消和错误处理
- 自动滚动到分析结果区域
- InfoCard组件优化，图标、标签和箭头排列在同一行

app/medications/[medicationId].tsx

@@ -5,10 +5,17 @@ import InfoCard from '@/components/ui/InfoCard';
 import { Colors } from '@/constants/Colors';
 import { DOSAGE_UNITS, DOSAGE_VALUES, FORM_LABELS, FORM_OPTIONS } from '@/constants/Medication';
 import { ROUTES } from '@/constants/Routes';
+import { useMembershipModal } from '@/contexts/MembershipModalContext';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
+import { useAuthGuard } from '@/hooks/useAuthGuard';
 import { useColorScheme } from '@/hooks/useColorScheme';
+import { useVipService } from '@/hooks/useVipService';
 import { medicationNotificationService } from '@/services/medicationNotifications';
-import { getMedicationById, getMedicationRecords } from '@/services/medications';
+import {
+  analyzeMedicationStream,
+  getMedicationById,
+  getMedicationRecords,
+} from '@/services/medications';
 import {
   deleteMedicationAction,
   fetchMedications,
@@ -41,6 +48,7 @@ import {
   View,
 } from 'react-native';
 import ImageViewing from 'react-native-image-viewing';
+import Markdown from 'react-native-markdown-display';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 
 const DEFAULT_IMAGE = require('@/assets/images/medicine/image-medicine.png');
@@ -60,6 +68,9 @@ export default function MedicationDetailScreen() {
   const colors = Colors[scheme];
   const insets = useSafeAreaInsets();
   const router = useRouter();
+  const { ensureLoggedIn } = useAuthGuard();
+  const { openMembershipModal } = useMembershipModal();
+  const { checkServiceAccess } = useVipService();
 
   const medications = useAppSelector(selectMedications);
   const medicationFromStore = medications.find((item) => item.id === medicationId);
@@ -86,6 +97,11 @@ export default function MedicationDetailScreen() {
   const [deactivateLoading, setDeactivateLoading] = useState(false);
   const [showImagePreview, setShowImagePreview] = useState(false);
   
+  // AI 分析相关状态
+  const [aiAnalysisLoading, setAiAnalysisLoading] = useState(false);
+  const [aiAnalysisContent, setAiAnalysisContent] = useState('');
+  const [aiAnalysisAbortController, setAiAnalysisAbortController] = useState<AbortController | null>(null);
+  
   // 剂量选择相关状态
   const [dosagePickerVisible, setDosagePickerVisible] = useState(false);
   const [dosageValuePicker, setDosageValuePicker] = useState(
@@ -100,6 +116,9 @@ export default function MedicationDetailScreen() {
   const [formPicker, setFormPicker] = useState<MedicationForm>(
     medicationFromStore?.form ?? 'capsule'
   );
+  
+  // ScrollView 引用，用于滚动到底部
+  const scrollViewRef = React.useRef<ScrollView>(null);
 
   useEffect(() => {
     if (!medicationFromStore) {
@@ -111,6 +130,10 @@ export default function MedicationDetailScreen() {
     if (medicationFromStore) {
       setMedication(medicationFromStore);
       setLoading(false);
+      // 如果服务端返回了 AI 分析结果，自动展示
+      if (medicationFromStore.aiAnalysis) {
+        setAiAnalysisContent(medicationFromStore.aiAnalysis);
+      }
     }
   }, [medicationFromStore]);
 
@@ -165,6 +188,10 @@ export default function MedicationDetailScreen() {
         console.log('[MEDICATION_DETAIL] API call successful', data);
         setMedication(data);
         setError(null);
+        // 如果服务端返回了 AI 分析结果，自动展示
+        if (data.aiAnalysis) {
+          setAiAnalysisContent(data.aiAnalysis);
+        }
       })
       .catch((err) => {
         if (abortController.signal.aborted) return;
@@ -635,6 +662,118 @@ export default function MedicationDetailScreen() {
     }
   }, [dispatch, formPicker, medication, updatePending]);
 
+  // AI 分析处理函数
+  const handleAiAnalysis = useCallback(async () => {
+    if (!medication || aiAnalysisLoading) return;
+    
+    // 1. 先验证用户是否登录
+    const isLoggedIn = await ensureLoggedIn();
+    if (!isLoggedIn) {
+      return; // 如果未登录，ensureLoggedIn 会自动跳转到登录页
+    }
+    
+    // 2. 检查用户是否是 VIP 或有剩余免费次数
+    const serviceAccess = checkServiceAccess();
+    if (!serviceAccess.canUseService) {
+      // 如果不能使用服务，弹出会员购买弹窗
+      openMembershipModal({
+        onPurchaseSuccess: () => {
+          // 购买成功后自动执行 AI 分析
+          handleAiAnalysis();
+        },
+      });
+      return;
+    }
+    
+    // 3. 通过验证，执行 AI 分析
+    // 重置状态
+    setAiAnalysisContent('');
+    setAiAnalysisLoading(true);
+    
+    // 滚动到底部，让用户看到分析内容
+    setTimeout(() => {
+      scrollViewRef.current?.scrollToEnd({ animated: true });
+    }, 100);
+    
+    // 创建 AbortController 用于取消
+    const controller = new AbortController();
+    setAiAnalysisAbortController(controller);
+    
+    try {
+      await analyzeMedicationStream(
+        medication.id,
+        {
+          onChunk: (chunk: string) => {
+            setAiAnalysisContent((prev) => prev + chunk);
+          },
+          onEnd: () => {
+            setAiAnalysisLoading(false);
+            setAiAnalysisAbortController(null);
+            // 重新加载药品详情以获取最新的 aiAnalysis 字段
+            if (medicationId) {
+              getMedicationById(medicationId)
+                .then((data) => {
+                  setMedication(data);
+                })
+                .catch((err) => {
+                  console.error('重新加载药品详情失败', err);
+                });
+            }
+          },
+          onError: (error: any) => {
+            console.error('[MEDICATION] AI 分析失败:', error);
+            
+            let errorMessage = 'AI 分析失败，请稍后重试';
+            
+            // 解析服务端返回的错误信息
+            if (error?.message) {
+              if (error.message.includes('[ERROR]')) {
+                errorMessage = error.message.replace('[ERROR]', '').trim();
+              } else if (error.message.includes('无权访问')) {
+                errorMessage = '无权访问此药物';
+              } else if (error.message.includes('不存在')) {
+                errorMessage = '药物不存在';
+              }
+            } else if (error?.status === 401) {
+              errorMessage = '请先登录';
+            } else if (error?.status === 403) {
+              errorMessage = '无权访问此药物';
+            } else if (error?.status === 404) {
+              errorMessage = '药物不存在';
+            }
+            
+            // 使用 Alert 弹窗显示错误
+            Alert.alert('分析失败', errorMessage);
+            
+            // 清空内容和加载状态
+            setAiAnalysisContent('');
+            setAiAnalysisLoading(false);
+            setAiAnalysisAbortController(null);
+          },
+        }
+      );
+    } catch (error) {
+      console.error('[MEDICATION] AI 分析异常:', error);
+      
+      // 使用 Alert 弹窗显示错误
+      Alert.alert('分析失败', '发起分析请求失败，请检查网络连接');
+      
+      // 清空内容和加载状态
+      setAiAnalysisContent('');
+      setAiAnalysisLoading(false);
+      setAiAnalysisAbortController(null);
+    }
+  }, [medication, aiAnalysisLoading, ensureLoggedIn, checkServiceAccess, openMembershipModal]);
+
+  // 组件卸载时取消 AI 分析请求
+  useEffect(() => {
+    return () => {
+      if (aiAnalysisAbortController) {
+        aiAnalysisAbortController.abort();
+      }
+    };
+  }, [aiAnalysisAbortController]);
+
   if (!medicationId) {
     return (
       <View style={styles.container}>
@@ -691,6 +830,7 @@ export default function MedicationDetailScreen() {
         </View>
       ) : medication ? (
         <ScrollView
+          ref={scrollViewRef}
           contentContainerStyle={[
             styles.content,
             {
@@ -831,6 +971,104 @@ export default function MedicationDetailScreen() {
               </View>
             </View>
           </Section>
+
+          {/* AI 分析结果展示 - 移动到底部 */}
+          {(aiAnalysisContent || aiAnalysisLoading) && (
+            <Section title="AI 用药分析" color={colors.text}>
+              <View style={[styles.aiAnalysisCard, { backgroundColor: colors.surface }]}>
+                {aiAnalysisLoading && !aiAnalysisContent && (
+                  <View style={styles.aiAnalysisLoading}>
+                    <ActivityIndicator color={colors.primary} size="small" />
+                    <Text style={[styles.aiAnalysisLoadingText, { color: colors.textSecondary }]}>
+                      正在分析用药信息...
+                    </Text>
+                  </View>
+                )}
+                
+                {aiAnalysisContent && (
+                  <View style={styles.aiAnalysisContentWrapper}>
+                    <Markdown
+                      style={{
+                        body: { color: colors.text, fontSize: 15, lineHeight: 24 },
+                        paragraph: { marginTop: 2, marginBottom: 8 },
+                        bullet_list: { marginVertical: 8 },
+                        ordered_list: { marginVertical: 8 },
+                        list_item: { flexDirection: 'row', marginVertical: 2 },
+                        code_inline: {
+                          backgroundColor: 'rgba(0,0,0,0.06)',
+                          borderRadius: 4,
+                          paddingHorizontal: 6,
+                          paddingVertical: 2,
+                          fontFamily: Platform.OS === 'ios' ? 'Menlo' : 'monospace',
+                        },
+                        code_block: {
+                          backgroundColor: 'rgba(0,0,0,0.06)',
+                          borderRadius: 8,
+                          paddingHorizontal: 12,
+                          paddingVertical: 8,
+                          fontFamily: Platform.OS === 'ios' ? 'Menlo' : 'monospace',
+                        },
+                        fence: {
+                          backgroundColor: 'rgba(0,0,0,0.06)',
+                          borderRadius: 8,
+                          paddingHorizontal: 12,
+                          paddingVertical: 8,
+                          fontFamily: Platform.OS === 'ios' ? 'Menlo' : 'monospace',
+                        },
+                        heading1: { fontSize: 20, fontWeight: '800', marginVertical: 8, color: colors.text },
+                        heading2: { fontSize: 18, fontWeight: '800', marginVertical: 8, color: colors.text },
+                        heading3: { fontSize: 16, fontWeight: '700', marginVertical: 6, color: colors.text },
+                        heading4: { fontSize: 15, fontWeight: '700', marginVertical: 4, color: colors.text },
+                        strong: { fontWeight: '700', color: colors.text },
+                        em: { fontStyle: 'italic' },
+                        link: { color: colors.primary, textDecorationLine: 'underline' },
+                        blockquote: {
+                          backgroundColor: 'rgba(0,0,0,0.03)',
+                          borderLeftWidth: 4,
+                          borderLeftColor: colors.primary,
+                          paddingHorizontal: 12,
+                          paddingVertical: 8,
+                          marginVertical: 8,
+                        },
+                        hr: {
+                          backgroundColor: colors.border,
+                          height: 1,
+                          marginVertical: 12,
+                        },
+                        table: {
+                          borderWidth: 1,
+                          borderColor: colors.border,
+                          borderRadius: 8,
+                          marginVertical: 8,
+                        },
+                        thead: {
+                          backgroundColor: 'rgba(0,0,0,0.03)',
+                        },
+                        tr: {
+                          borderBottomWidth: 1,
+                          borderBottomColor: colors.border,
+                        },
+                        th: {
+                          padding: 8,
+                          fontWeight: '700',
+                        },
+                        td: {
+                          padding: 8,
+                        },
+                      }}
+                    >
+                      {aiAnalysisContent}
+                    </Markdown>
+                    {aiAnalysisLoading && (
+                      <View style={styles.aiAnalysisStreaming}>
+                        <ActivityIndicator color={colors.primary} size="small" />
+                      </View>
+                    )}
+                  </View>
+                )}
+              </View>
+            </Section>
+          )}
         </ScrollView>
       ) : null}
 
@@ -843,27 +1081,66 @@ export default function MedicationDetailScreen() {
             },
           ]}
         >
-          <TouchableOpacity
-            activeOpacity={0.9}
-            onPress={() => setDeleteSheetVisible(true)}
-          >
-            {isLiquidGlassAvailable() ? (
-              <GlassView
-                style={styles.deleteButton}
-                glassEffectStyle="regular"
-                tintColor="rgba(239, 68, 68, 0.8)"
-                isInteractive={true}
-              >
-                <Ionicons name='trash-outline' size={18} color='#fff' />
-                <Text style={styles.deleteButtonText}>删除该药品</Text>
-              </GlassView>
-            ) : (
-              <View style={[styles.deleteButton, styles.fallbackDeleteButton]}>
-                <Ionicons name='trash-outline' size={18} color='#fff' />
-                <Text style={styles.deleteButtonText}>删除该药品</Text>
-              </View>
-            )}
-          </TouchableOpacity>
+          <View style={styles.footerButtonContainer}>
+            {/* AI 分析按钮 - 占 2/3 宽度 */}
+            <TouchableOpacity
+              style={styles.aiAnalysisButtonWrapper}
+              activeOpacity={0.9}
+              onPress={handleAiAnalysis}
+              disabled={aiAnalysisLoading}
+            >
+              {isLiquidGlassAvailable() ? (
+                <GlassView
+                  style={styles.aiAnalysisButton}
+                  glassEffectStyle="regular"
+                  tintColor="rgba(59, 130, 246, 0.8)"
+                  isInteractive={true}
+                >
+                  {aiAnalysisLoading ? (
+                    <ActivityIndicator size="small" color="#fff" />
+                  ) : (
+                    <Ionicons name="sparkles-outline" size={18} color="#fff" />
+                  )}
+                  <Text style={styles.aiAnalysisButtonText}>
+                    {aiAnalysisLoading ? '分析中...' : 'AI 分析'}
+                  </Text>
+                </GlassView>
+              ) : (
+                <View style={[styles.aiAnalysisButton, styles.fallbackAiButton]}>
+                  {aiAnalysisLoading ? (
+                    <ActivityIndicator size="small" color="#fff" />
+                  ) : (
+                    <Ionicons name="sparkles-outline" size={18} color="#fff" />
+                  )}
+                  <Text style={styles.aiAnalysisButtonText}>
+                    {aiAnalysisLoading ? '分析中...' : 'AI 分析'}
+                  </Text>
+                </View>
+              )}
+            </TouchableOpacity>
+
+            {/* 删除按钮 - 占 1/3 宽度 */}
+            <TouchableOpacity
+              style={styles.deleteButtonWrapper}
+              activeOpacity={0.9}
+              onPress={() => setDeleteSheetVisible(true)}
+            >
+              {isLiquidGlassAvailable() ? (
+                <GlassView
+                  style={styles.deleteButton}
+                  glassEffectStyle="regular"
+                  tintColor="rgba(239, 68, 68, 0.8)"
+                  isInteractive={true}
+                >
+                  <Ionicons name="trash-outline" size={18} color="#fff" />
+                </GlassView>
+              ) : (
+                <View style={[styles.deleteButton, styles.fallbackDeleteButton]}>
+                  <Ionicons name="trash-outline" size={18} color="#fff" />
+                </View>
+              )}
+            </TouchableOpacity>
+          </View>
         </View>
       ) : null}
 
@@ -1470,6 +1747,72 @@ const styles = StyleSheet.create({
     shadowRadius: 20,
     elevation: 6,
   },
+  // 底部按钮容器样式
+  footerButtonContainer: {
+    flexDirection: 'row',
+    gap: 12,
+  },
+  aiAnalysisButtonWrapper: {
+    flex: 2, // 占 2/3 宽度
+  },
+  deleteButtonWrapper: {
+    flex: 1, // 占 1/3 宽度
+  },
+  aiAnalysisButton: {
+    height: 56,
+    borderRadius: 24,
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'center',
+    gap: 8,
+    overflow: 'hidden',
+  },
+  fallbackAiButton: {
+    backgroundColor: '#3B82F6',
+    shadowColor: 'rgba(59,130,246,0.4)',
+    shadowOffset: { width: 0, height: 10 },
+    shadowOpacity: 1,
+    shadowRadius: 20,
+    elevation: 6,
+  },
+  aiAnalysisButtonText: {
+    fontSize: 17,
+    fontWeight: '700',
+    color: '#fff',
+  },
+  // AI 分析卡片样式
+  aiAnalysisCard: {
+    borderRadius: 24,
+    padding: 20,
+    minHeight: 100,
+    shadowColor: '#000',
+    shadowOpacity: 0.06,
+    shadowRadius: 12,
+    shadowOffset: { width: 0, height: 3 },
+    elevation: 3,
+    borderWidth: 1,
+    borderColor: 'rgba(0, 0, 0, 0.04)',
+  },
+  aiAnalysisLoading: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    gap: 12,
+    paddingVertical: 12,
+  },
+  aiAnalysisLoadingText: {
+    fontSize: 15,
+  },
+  aiAnalysisContentWrapper: {
+    gap: 12,
+  },
+  aiAnalysisText: {
+    fontSize: 15,
+    lineHeight: 24,
+  },
+  aiAnalysisStreaming: {
+    alignSelf: 'flex-start',
+    marginTop: 8,
+  },
   deleteButtonText: {
     fontSize: 17,
     fontWeight: '700',