feat: Added LLM factory initialization functionality and knowledge base related API interfaces (#13472)

### What problem does this PR solve?

feat: Added LLM factory initialization functionality and knowledge base
related API interfaces

refactor(dao): Refactored the TenantLLMDAO query method
feat(handler): Implemented knowledge base related API endpoints
feat(service): Added LLM API key setting functionality
feat(model): Extended the knowledge base model definition
feat(config): Added default user LLM configuration

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

internal/init_data/llm_init.go

@@ -0,0 +1,157 @@
+//
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+package init_data
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	"ragflow/internal/dao"
+	"ragflow/internal/model"
+)
+
+// LLMFactoryConfig represents a single LLM factory configuration
+type LLMFactoryConfig struct {
+	Name   string        `json:"name"`
+	Logo   string        `json:"logo"`
+	Tags   string        `json:"tags"`
+	Status string        `json:"status"`
+	Rank   string        `json:"rank"`
+	LLM    []LLMConfig   `json:"llm"`
+}
+
+// LLMConfig represents a single LLM model configuration
+type LLMConfig struct {
+	LLMName   string `json:"llm_name"`
+	Tags      string `json:"tags"`
+	MaxTokens int64  `json:"max_tokens"`
+	ModelType string `json:"model_type"`
+	IsTools   bool   `json:"is_tools"`
+}
+
+// LLMFactoriesFile represents the structure of llm_factories.json
+type LLMFactoriesFile struct {
+	FactoryLLMInfos []LLMFactoryConfig `json:"factory_llm_infos"`
+}
+
+// InitLLMFactory initializes LLM factories and models from JSON file
+func InitLLMFactory() error {
+	configPath := filepath.Join(getProjectBaseDirectory(), "conf", "llm_factories.json")
+	
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		return fmt.Errorf("failed to read llm_factories.json: %w", err)
+	}
+
+	var fileData LLMFactoriesFile
+	if err := json.Unmarshal(data, &fileData); err != nil {
+		return fmt.Errorf("failed to parse llm_factories.json: %w", err)
+	}
+
+	db := dao.DB
+
+	for _, factory := range fileData.FactoryLLMInfos {
+		status := factory.Status
+		if status == "" {
+			status = "1"
+		}
+
+		llmFactory := &model.LLMFactories{
+			Name:   factory.Name,
+			Logo:   stringPtr(factory.Logo),
+			Tags:   factory.Tags,
+			Rank:   parseInt64(factory.Rank),
+			Status: &status,
+		}
+
+		var existingFactory model.LLMFactories
+		result := db.Where("name = ?", factory.Name).First(&existingFactory)
+		if result.Error != nil {
+			if err := db.Create(llmFactory).Error; err != nil {
+				log.Printf("Failed to create LLM factory %s: %v", factory.Name, err)
+				continue
+			}
+		} else {
+			if err := db.Model(&model.LLMFactories{}).Where("name = ?", factory.Name).Updates(map[string]interface{}{
+				"logo":   llmFactory.Logo,
+				"tags":   llmFactory.Tags,
+				"rank":   llmFactory.Rank,
+				"status": llmFactory.Status,
+			}).Error; err != nil {
+				log.Printf("Failed to update LLM factory %s: %v", factory.Name, err)
+			}
+		}
+
+		for _, llm := range factory.LLM {
+			llmStatus := "1"
+			llmModel := &model.LLM{
+				LLMName:   llm.LLMName,
+				ModelType: llm.ModelType,
+				FID:       factory.Name,
+				MaxTokens: llm.MaxTokens,
+				Tags:      llm.Tags,
+				IsTools:   llm.IsTools,
+				Status:    &llmStatus,
+			}
+
+			var existingLLM model.LLM
+			result := db.Where("llm_name = ? AND fid = ?", llm.LLMName, factory.Name).First(&existingLLM)
+			if result.Error != nil {
+				if err := db.Create(llmModel).Error; err != nil {
+					log.Printf("Failed to create LLM %s/%s: %v", factory.Name, llm.LLMName, err)
+				}
+			} else {
+				if err := db.Model(&model.LLM{}).Where("llm_name = ? AND fid = ?", llm.LLMName, factory.Name).Updates(map[string]interface{}{
+					"model_type": llmModel.ModelType,
+					"max_tokens": llmModel.MaxTokens,
+					"tags":       llmModel.Tags,
+					"is_tools":   llmModel.IsTools,
+					"status":     llmModel.Status,
+				}).Error; err != nil {
+					log.Printf("Failed to update LLM %s/%s: %v", factory.Name, llm.LLMName, err)
+				}
+			}
+		}
+	}
+
+	log.Println("LLM factories initialized successfully")
+	return nil
+}
+
+func getProjectBaseDirectory() string {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "."
+	}
+	return cwd
+}
+
+func stringPtr(s string) *string {
+	if s == "" {
+		return nil
+	}
+	return &s
+}
+
+func parseInt64(s string) int64 {
+	var result int64
+	fmt.Sscanf(s, "%d", &result)
+	return result
+}