feat(group): 添加分组级别模型路由配置功能

支持为分组配置模型路由规则，可以指定特定模型模式优先使用的账号列表。

  - 新增 model_routing 字段存储路由配置（JSONB格式，支持通配符匹配）

  - 新增 model_routing_enabled 字段控制是否启用路由

  - 更新后端 handler/service/repository 支持路由配置的增删改查

  - 更新前端 GroupsView 添加路由配置界面

  - 添加数据库迁移脚本 040/041

backend/internal/repository/api_key_repo.go

@@ -136,6 +136,8 @@ func (r *apiKeyRepository) GetByKeyForAuth(ctx context.Context, key string) (*se
 				group.FieldImagePrice4k,
 				group.FieldClaudeCodeOnly,
 				group.FieldFallbackGroupID,
+				group.FieldModelRoutingEnabled,
+				group.FieldModelRouting,
 			)
 		}).
 		Only(ctx)
@@ -422,6 +424,8 @@ func groupEntityToService(g *dbent.Group) *service.Group {
 		DefaultValidityDays: g.DefaultValidityDays,
 		ClaudeCodeOnly:      g.ClaudeCodeOnly,
 		FallbackGroupID:     g.FallbackGroupID,
+		ModelRouting:        g.ModelRouting,
+		ModelRoutingEnabled: g.ModelRoutingEnabled,
 		CreatedAt:           g.CreatedAt,
 		UpdatedAt:           g.UpdatedAt,
 	}

backend/internal/repository/group_repo.go

@@ -49,7 +49,13 @@ func (r *groupRepository) Create(ctx context.Context, groupIn *service.Group) er
 		SetNillableImagePrice4k(groupIn.ImagePrice4K).
 		SetDefaultValidityDays(groupIn.DefaultValidityDays).
 		SetClaudeCodeOnly(groupIn.ClaudeCodeOnly).
-		SetNillableFallbackGroupID(groupIn.FallbackGroupID)
+		SetNillableFallbackGroupID(groupIn.FallbackGroupID).
+		SetModelRoutingEnabled(groupIn.ModelRoutingEnabled)
+
+	// 设置模型路由配置
+	if groupIn.ModelRouting != nil {
+		builder = builder.SetModelRouting(groupIn.ModelRouting)
+	}
 
 	created, err := builder.Save(ctx)
 	if err == nil {
@@ -101,7 +107,8 @@ func (r *groupRepository) Update(ctx context.Context, groupIn *service.Group) er
 		SetNillableImagePrice2k(groupIn.ImagePrice2K).
 		SetNillableImagePrice4k(groupIn.ImagePrice4K).
 		SetDefaultValidityDays(groupIn.DefaultValidityDays).
-		SetClaudeCodeOnly(groupIn.ClaudeCodeOnly)
+		SetClaudeCodeOnly(groupIn.ClaudeCodeOnly).
+		SetModelRoutingEnabled(groupIn.ModelRoutingEnabled)
 
 	// 处理 FallbackGroupID：nil 时清除，否则设置
 	if groupIn.FallbackGroupID != nil {
@@ -110,6 +117,13 @@ func (r *groupRepository) Update(ctx context.Context, groupIn *service.Group) er
 		builder = builder.ClearFallbackGroupID()
 	}
 
+	// 处理 ModelRouting：nil 时清除，否则设置
+	if groupIn.ModelRouting != nil {
+		builder = builder.SetModelRouting(groupIn.ModelRouting)
+	} else {
+		builder = builder.ClearModelRouting()
+	}
+
 	updated, err := builder.Save(ctx)
 	if err != nil {
 		return translatePersistenceError(err, service.ErrGroupNotFound, service.ErrGroupExists)