refactor: unified brand naming to BoosChat

Rebrand all user-facing product name references from legacy
Chinese name to unified "BoosChat" across frontend components,
metadata, test fixtures, and documentation.

cmd/testdata/kb/kb.go

@@ -152,10 +152,10 @@ func ensureKnowledgeBase(db *gorm.DB) (*models.KnowledgeBase, error) {
 
 func ensureFAQKnowledgeBase(db *gorm.DB) (*models.KnowledgeBase, error) {
 	now := time.Now()
-	item := repositories.KnowledgeBaseRepository.FindOne(db, sqls.NewCnd().Eq("name", "贝壳客服平台 FAQ"))
+	item := repositories.KnowledgeBaseRepository.FindOne(db, sqls.NewCnd().Eq("name", "BoosChat 客服平台 FAQ"))
 	if item == nil {
 		item = &models.KnowledgeBase{
-			Name:                  "贝壳客服平台 FAQ",
+			Name:                  "BoosChat 客服平台 FAQ",
 			Description:           "模拟真实客服场景的 FAQ 测试数据，覆盖账号、坐席、机器人、知识库、工单、计费与发票等常见问题。",
 			KnowledgeType:         string(enums.KnowledgeBaseTypeFAQ),
 			Status:                enums.StatusOk,