refactor: UI界面和代码重构

1. 简化 AnalysisViewModel 使用 Flow 组合
2. 改进 AnalysisScreen 的布局结构
3. 优化 CategoryDetailScreen 的视觉层次
4. 修复统计中成员名称的处理

app/src/main/java/com/yovinchen/bookkeeping/ui/screen/CategoryDetailScreen.kt

@@ -62,27 +62,74 @@ fun CategoryDetailScreen(
                 .padding(padding),
             horizontalAlignment = Alignment.CenterHorizontally
         ) {
+            // 第一部分：总支出
             item {
+                Card(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(16.dp),
+                    elevation = CardDefaults.cardElevation(defaultElevation = 4.dp)
+                ) {
+                    Column(
+                        modifier = Modifier
+                            .padding(16.dp),
+                        horizontalAlignment = Alignment.CenterHorizontally
+                    ) {
+                        Text(
+                            text = "总支出",
+                            style = MaterialTheme.typography.titleMedium
+                        )
+                        Spacer(modifier = Modifier.height(8.dp))
                         Text(
                             text = NumberFormat.getCurrencyInstance(Locale.CHINA).format(total),
                             style = MaterialTheme.typography.headlineMedium,
-                    modifier = Modifier.padding(16.dp)
+                            fontWeight = FontWeight.Bold
                         )
                     }
+                }
+            }
 
+            // 第二部分：扇形图
             item {
+                Card(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 16.dp, vertical = 8.dp),
+                    elevation = CardDefaults.cardElevation(defaultElevation = 4.dp)
+                ) {
+                    Column(
+                        modifier = Modifier
+                            .padding(16.dp),
+                        horizontalAlignment = Alignment.CenterHorizontally
+                    ) {
+                        Text(
+                            text = "成员分布",
+                            style = MaterialTheme.typography.titleMedium,
+                            modifier = Modifier.padding(bottom = 16.dp)
+                        )
                         CategoryPieChart(
                             categoryData = memberStats.map { Pair(it.category, it.percentage.toFloat()) },
                             memberData = emptyList(),
                             currentViewMode = false,
                             modifier = Modifier
                                 .fillMaxWidth()
-                        .padding(16.dp),
+                                .height(200.dp),
                             onCategoryClick = { memberName -> onNavigateToMemberDetail(memberName) }
                         )
                     }
+                }
+            }
 
-            // 按日期分组记录
+            // 第三部分：详细信息
+            item {
+                Text(
+                    text = "详细记录",
+                    style = MaterialTheme.typography.titleMedium,
+                    modifier = Modifier.padding(16.dp)
+                )
+            }
+
+            // 按日期分组的记录列表
             val groupedRecords = records.groupBy { record ->
                 SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(record.date)
             }.toSortedMap(compareByDescending { it })

app/src/main/java/com/yovinchen/bookkeeping/ui/screen/MemberDetailScreen.kt

@@ -75,7 +75,7 @@ fun MemberDetailScreen(
                         horizontalAlignment = Alignment.CenterHorizontally
                     ) {
                         Text(
-                            text = "当前分类总支出",
+                            text = "总支出",
                             style = MaterialTheme.typography.titleMedium
                         )
                         Spacer(modifier = Modifier.height(8.dp))