refactor: remove knowledge base references from AI agent model and related services

- Removed KnowledgeIDs from CreateAIAgentRequest and AIAgentResponse.
- Updated buildAIAgentResponseWithLocale to eliminate knowledge base name retrieval.
- Refactored AI agent repository and service to remove knowledge base handling.
- Adjusted dashboard service to no longer track AI agents without knowledge bases.
- Modified knowledge base service to check for workflow references instead of AI agent references.
- Updated frontend components to remove knowledge base selection and display.
- Enhanced workflow validation to ensure knowledge retrieve nodes have associated knowledge bases.

internal/repositories/ai_agent_repository.go

@@ -1,11 +1,7 @@
 package repositories
 
 import (
-	"strconv"
-
 	"agent-desk/internal/models"
-	"agent-desk/internal/pkg/enums"
-
 	"agent-desk/internal/pkg/httpx/params"
 
 	"github.com/mlogclub/simple/sqls"
@@ -112,16 +108,3 @@ func (r *aIAgentRepository) FindByIds(db *gorm.DB, ids []int64) []models.AIAgent
 	db.Where("id IN ?", ids).Find(&list)
 	return list
 }
-
-func (r *aIAgentRepository) FindByKnowledgeBaseID(db *gorm.DB, knowledgeBaseID int64) (list []models.AIAgent) {
-	id := strconv.FormatInt(knowledgeBaseID, 10)
-	db.Where(
-		"(knowledge_ids = ? OR knowledge_ids LIKE ? OR knowledge_ids LIKE ? OR knowledge_ids LIKE ?) AND status <> ?",
-		id,
-		id+",%",
-		"%,"+id,
-		"%,"+id+",%",
-		enums.StatusDeleted,
-	).Find(&list)
-	return
-}