fix: 显示分类预算并阻止同分类重复创建

lib/data/repositories/local/local_budget_repository.dart

@@ -46,16 +46,16 @@ class LocalBudgetRepository implements BudgetRepository {
     // 每条新建预算分配一个 UUID,跨设备 LWW 用。syncId 在 DB schema 上允许
     // NULL,只是为了 v22 migration 对老数据兼容;新建走这里永远填。
     return await db.into(db.budgets).insert(
-      BudgetsCompanion.insert(
-        ledgerId: ledgerId,
-        type: d.Value(type),
-        categoryId: d.Value(categoryId),
-        amount: amount,
-        period: d.Value(period),
-        startDay: d.Value(startDay),
-        syncId: d.Value(_uuid.v4()),
-      ),
-    );
+          BudgetsCompanion.insert(
+            ledgerId: ledgerId,
+            type: d.Value(type),
+            categoryId: d.Value(categoryId),
+            amount: amount,
+            period: d.Value(period),
+            startDay: d.Value(startDay),
+            syncId: d.Value(_uuid.v4()),
+          ),
+        );
   }
 
   @override
@@ -78,8 +78,7 @@ class LocalBudgetRepository implements BudgetRepository {
   @override
   Future<void> deleteBudget(int id) async {
     // 先获取预算信息，判断是否为总预算
-    final budget = await (db.select(db.budgets)
-          ..where((b) => b.id.equals(id)))
+    final budget = await (db.select(db.budgets)..where((b) => b.id.equals(id)))
         .getSingleOrNull();
 
     if (budget == null) return;
@@ -99,28 +98,43 @@ class LocalBudgetRepository implements BudgetRepository {
   Future<Budget?> getTotalBudget(int ledgerId) async {
     // 使用 .get() 然后取第一个，避免多条脏数据时报错
     final budgets = await (db.select(db.budgets)
-          ..where((b) => b.ledgerId.equals(ledgerId) & b.type.equals('total') & b.enabled.equals(true))
+          ..where((b) =>
+              b.ledgerId.equals(ledgerId) &
+              b.type.equals('total') &
+              b.enabled.equals(true))
           ..orderBy([(b) => d.OrderingTerm(expression: b.createdAt)]))
         .get();
     return budgets.firstOrNull;
   }
 
   @override
   Future<List<Budget>> getCategoryBudgets(int ledgerId) async {
-    return await (db.select(db.budgets)
-          ..where((b) => b.ledgerId.equals(ledgerId) & b.type.equals('category') & b.enabled.equals(true)))
+    final rows = await (db.select(db.budgets)
+          ..where((b) =>
+              b.ledgerId.equals(ledgerId) &
+              b.type.equals('category') &
+              b.enabled.equals(true)))
         .get();
+
+    // 老版本允许同一分类创建多条预算，Cloud 的读接口按 syncId 字典序最大
+    // 的记录展示。本地采用相同 keeper 规则，避免升级后把历史重复行全部画
+    // 出来；数据仍保留，后续同步/清理不会因一次只读查询而丢失。
+    final byCategory = <int, Budget>{};
+    for (final row in rows) {
+      final categoryId = row.categoryId;
+      if (categoryId == null) continue;
+      final current = byCategory[categoryId];
+      if (current == null || _preferBudget(row, current)) {
+        byCategory[categoryId] = row;
+      }
+    }
+    return byCategory.values.toList();
   }
 
   @override
   Future<Budget?> getBudgetByCategory(int ledgerId, int categoryId) async {
-    return await (db.select(db.budgets)
-          ..where((b) =>
-              b.ledgerId.equals(ledgerId) &
-              b.type.equals('category') &
-              b.categoryId.equals(categoryId) &
-              b.enabled.equals(true)))
-        .getSingleOrNull();
+    final budgets = await getCategoryBudgets(ledgerId);
+    return budgets.where((b) => b.categoryId == categoryId).firstOrNull;
   }
 
   @override
@@ -316,4 +330,13 @@ class LocalBudgetRepository implements BudgetRepository {
     if (v is num) return v.toDouble();
     return 0.0;
   }
+
+  bool _preferBudget(Budget candidate, Budget current) {
+    final candidateSyncId = candidate.syncId ?? '';
+    final currentSyncId = current.syncId ?? '';
+    if (candidateSyncId != currentSyncId) {
+      return candidateSyncId.compareTo(currentSyncId) > 0;
+    }
+    return candidate.createdAt.isAfter(current.createdAt);
+  }
 }

lib/l10n/app_en.arb

@@ -2485,6 +2485,7 @@
   "budgetAmountHint": "Enter budget amount",
   "budgetCategoryLabel": "Select Category",
   "budgetCategoryHint": "Select budget category",
+  "budgetCategoryAlreadyExists": "This category already has a budget",
   "budgetStartDayLabel": "Start Day",
   "budgetPeriodLabel": "Period",
   "budgetSaveSuccess": "Budget saved",

lib/l10n/app_ko.arb

@@ -1746,6 +1746,7 @@
   "budgetAmountHint": "예산 금액을 입력하세요",
   "budgetCategoryLabel": "카테고리 선택",
   "budgetCategoryHint": "예산 카테고리를 선택하세요",
+  "budgetCategoryAlreadyExists": "이 카테고리에는 이미 예산이 있습니다",
   "budgetStartDayLabel": "시작일",
   "budgetPeriodLabel": "기간",
   "budgetSaveSuccess": "예산이 저장되었습니다",

lib/l10n/app_localizations.dart

@@ -10970,6 +10970,12 @@ abstract class AppLocalizations {
   /// **'Select budget category'**
   String get budgetCategoryHint;
 
+  /// No description provided for @budgetCategoryAlreadyExists.
+  ///
+  /// In en, this message translates to:
+  /// **'This category already has a budget'**
+  String get budgetCategoryAlreadyExists;
+
   /// No description provided for @budgetStartDayLabel.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_en.dart

@@ -5740,6 +5740,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get budgetCategoryHint => 'Select budget category';
 
+  @override
+  String get budgetCategoryAlreadyExists => 'This category already has a budget';
+
   @override
   String get budgetStartDayLabel => 'Start Day';
 

lib/l10n/app_localizations_ko.dart

@@ -5740,6 +5740,9 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get budgetCategoryHint => '예산 카테고리를 선택하세요';
 
+  @override
+  String get budgetCategoryAlreadyExists => '이 카테고리에는 이미 예산이 있습니다';
+
   @override
   String get budgetStartDayLabel => '시작일';
 

lib/l10n/app_localizations_zh.dart

@@ -5740,6 +5740,9 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get budgetCategoryHint => '请选择预算分类';
 
+  @override
+  String get budgetCategoryAlreadyExists => '该分类已设置预算';
+
   @override
   String get budgetStartDayLabel => '起始日';
 
@@ -13252,6 +13255,9 @@ class AppLocalizationsZhTw extends AppLocalizationsZh {
   @override
   String get budgetCategoryHint => '請選擇預算分類';
 
+  @override
+  String get budgetCategoryAlreadyExists => '該分類已設定預算';
+
   @override
   String get budgetStartDayLabel => '起始日';
 

lib/l10n/app_zh.arb

@@ -2415,6 +2415,7 @@
   "budgetAmountHint": "请输入预算金额",
   "budgetCategoryLabel": "选择分类",
   "budgetCategoryHint": "请选择预算分类",
+  "budgetCategoryAlreadyExists": "该分类已设置预算",
   "budgetStartDayLabel": "起始日",
   "budgetPeriodLabel": "周期",
   "budgetSaveSuccess": "预算保存成功",

lib/l10n/app_zh_TW.arb

@@ -577,6 +577,7 @@
   "budgetAmountLabel": "預算金額",
   "budgetCategoryBudgets": "分類預算",
   "budgetCategoryHint": "請選擇預算分類",
+  "budgetCategoryAlreadyExists": "該分類已設定預算",
   "budgetCategoryLabel": "選擇分類",
   "budgetDailyAvailable": "日均可用 {amount}",
   "@budgetDailyAvailable": {

lib/pages/budget/budget_edit_page.dart

@@ -196,9 +196,11 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
                       SizedBox(height: 12.0.scaled(context, ref)),
                       TextField(
                         controller: _amountController,
-                        keyboardType: const TextInputType.numberWithOptions(decimal: true),
+                        keyboardType: const TextInputType.numberWithOptions(
+                            decimal: true),
                         inputFormatters: [
-                          FilteringTextInputFormatter.allow(RegExp(r'^\d+\.?\d{0,2}')),
+                          FilteringTextInputFormatter.allow(
+                              RegExp(r'^\d+\.?\d{0,2}')),
                         ],
                         style: TextStyle(
                           fontSize: 24,
@@ -257,7 +259,8 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
                 : BeeTokens.surface(context),
             borderRadius: BorderRadius.circular(12),
             border: Border.all(
-              color: isSelected && !disabled ? primary : BeeTokens.border(context),
+              color:
+                  isSelected && !disabled ? primary : BeeTokens.border(context),
               width: isSelected && !disabled ? 2 : 1,
             ),
           ),
@@ -266,15 +269,21 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
               Icon(
                 icon,
                 size: 32.0.scaled(context, ref),
-                color: isSelected && !disabled ? primary : BeeTokens.iconSecondary(context),
+                color: isSelected && !disabled
+                    ? primary
+                    : BeeTokens.iconSecondary(context),
               ),
               SizedBox(height: 8.0.scaled(context, ref)),
               Text(
                 label,
                 style: TextStyle(
                   fontSize: 14,
-                  fontWeight: isSelected && !disabled ? FontWeight.w600 : FontWeight.w400,
-                  color: isSelected && !disabled ? primary : BeeTokens.textSecondary(context),
+                  fontWeight: isSelected && !disabled
+                      ? FontWeight.w600
+                      : FontWeight.w400,
+                  color: isSelected && !disabled
+                      ? primary
+                      : BeeTokens.textSecondary(context),
                 ),
               ),
             ],
@@ -302,7 +311,10 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
                 width: 36.0.scaled(context, ref),
                 height: 36.0.scaled(context, ref),
                 decoration: BoxDecoration(
-                  color: Theme.of(context).colorScheme.primary.withValues(alpha: 0.1),
+                  color: Theme.of(context)
+                      .colorScheme
+                      .primary
+                      .withValues(alpha: 0.1),
                   borderRadius: BorderRadius.circular(8),
                 ),
                 child: Icon(
@@ -350,11 +362,22 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
 
   Future<void> _selectCategory() async {
     final repo = ref.read(repositoryProvider);
+    final ledgerId = ref.read(currentLedgerIdProvider);
     final categories = await repo.getAllCategories();
-
-    // 只显示支出类父分类
+    final existingBudgets = await repo.getCategoryBudgets(ledgerId);
+    final usedCategoryIds = existingBudgets
+        .where((b) => b.id != widget.budget?.id && b.categoryId != null)
+        .map((b) => b.categoryId!)
+        .toSet();
+
+    // 只显示尚未设置预算的支出类父分类。此前所有分类始终可选，导致同一
+    // 分类能生成多个 syncId；Cloud 读接口会去重，所以表现为同步计数增加、
+    // Web 列表却看不到新增记录。
     final expenseCategories = categories
-        .where((c) => c.kind == 'expense' && c.parentId == null)
+        .where((c) =>
+            c.kind == 'expense' &&
+            c.parentId == null &&
+            !usedCategoryIds.contains(c.id))
         .toList();
 
     if (!mounted) return;
@@ -461,12 +484,26 @@ class _BudgetEditPageState extends ConsumerState<BudgetEditPage> {
       return;
     }
 
+    final repo = ref.read(repositoryProvider);
+    final ledgerId = ref.read(currentLedgerIdProvider);
+
+    // 选择器过滤负责正常交互；保存前再检查一次，防止弹窗打开期间另一设备
+    // 同步进同分类预算，或旧数据/并发操作绕过 UI 造成重复。
+    if (!_isEditing && _type == 'category') {
+      final existing =
+          await repo.getBudgetByCategory(ledgerId, _selectedCategoryId!);
+      if (existing != null) {
+        if (mounted) {
+          showToast(context, l10n.budgetCategoryAlreadyExists);
+        }
+        return;
+      }
+    }
+
+    if (!mounted) return;
     setState(() => _isLoading = true);
 
     try {
-      final repo = ref.read(repositoryProvider);
-      final ledgerId = ref.read(currentLedgerIdProvider);
-
       if (_isEditing) {
         await repo.updateBudget(
           widget.budget!.id,

lib/pages/budget/budget_page.dart

@@ -65,7 +65,12 @@ class BudgetPage extends ConsumerWidget {
         ref.watch(currentLedgerProvider).asData?.value?.currency ?? 'CNY';
     final currencySymbol = getCurrencySymbol(currencyCode);
 
-    if (overview == null || overview.totalBudget == null) {
+    final categoryBudgets = overview?.categoryBudgets ?? const [];
+    final hasTotalBudget = overview?.totalBudget != null;
+
+    // 分类预算可以独立于总预算存在。旧逻辑只判断 totalBudget，导致 Web 或
+    // App 创建的分类预算已经落库、同步计数也正确，但整个页面仍显示为空。
+    if (!hasTotalBudget && categoryBudgets.isEmpty) {
       return _buildEmptyState(context, ref, l10n);
     }
 
@@ -75,21 +80,22 @@ class BudgetPage extends ConsumerWidget {
         vertical: 8.0.scaled(context, ref),
       ),
       children: [
-        // 总预算概览卡片
-        _buildTotalBudgetCard(context, ref, overview, l10n, currencySymbol),
-        SizedBox(height: 12.0.scaled(context, ref)),
+        // 总预算概览卡片（分类预算不要求先创建总预算）
+        if (hasTotalBudget) ...[
+          _buildTotalBudgetCard(context, ref, overview!, l10n, currencySymbol),
+          SizedBox(height: 12.0.scaled(context, ref)),
+        ],
         // 分类预算列表
-        if (overview.categoryBudgets.isNotEmpty)
+        if (categoryBudgets.isNotEmpty)
           _buildCategoryBudgetsCard(
-              context, ref, overview.categoryBudgets, l10n, currencySymbol),
+              context, ref, categoryBudgets, l10n, currencySymbol),
         SizedBox(height: 12.0.scaled(context, ref)),
         // 首页显示开关
         _buildSettingsCard(context, ref, l10n),
       ],
     );
   }
 
-
   Widget _buildEmptyState(
       BuildContext context, WidgetRef ref, AppLocalizations l10n) {
     // §7 共享账本 Editor 视角:预算空时不显示"添加"CTA(owner-only)
@@ -118,8 +124,8 @@ class BudgetPage extends ConsumerWidget {
           if (!isEditorInShared)
             ElevatedButton.icon(
               onPressed: () => _addBudget(context),
-              icon: Icon(Icons.add,
-                  color: BeeTokens.buttonPrimaryText(context)),
+              icon:
+                  Icon(Icons.add, color: BeeTokens.buttonPrimaryText(context)),
               label: Text(l10n.budgetAddTotal),
               style: ElevatedButton.styleFrom(
                 backgroundColor: BeeTokens.buttonPrimary(context),