Remove unused codes (#15579)

### What problem does this PR solve?

Remove unused code.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/server/model_provider.go

@@ -1,116 +0,0 @@
-//
-//  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 server
-
-import (
-	"encoding/json"
-	"fmt"
-	"os"
-	"sync"
-)
-
-// ModelProvider represents a model provider configuration
-type ModelProvider struct {
-	Name       string `json:"name"`
-	Logo       string `json:"logo"`
-	Tags       string `json:"tags"`
-	Status     string `json:"status"`
-	Rank       string `json:"rank"`
-	LLMs       []LLM  `json:"llm"`
-	DefaultURL string `json:"url,omitempty"`
-}
-
-// LLM represents a language model within a provider
-type LLM struct {
-	LLMName   string `json:"llm_name"`
-	Tags      string `json:"tags"`
-	MaxTokens int    `json:"max_tokens"`
-	ModelType string `json:"model_type"`
-	IsTools   bool   `json:"is_tools"`
-}
-
-var (
-	modelProviders     []ModelProvider
-	modelProviderMap   map[string]int // name -> index in modelProviders slice
-	modelProvidersOnce sync.Once
-	modelProvidersErr  error
-)
-
-// LoadModelProviders loads model providers from JSON file.
-// If path is empty, it defaults to "conf/model_providers.json" relative to current working directory.
-func LoadModelProviders(path string) error {
-	modelProvidersOnce.Do(func() {
-		if path == "" {
-			path = "conf/llm_factories.json"
-			//path = "conf/model_providers.json"
-		}
-
-		data, err := os.ReadFile(path)
-		if err != nil {
-			modelProvidersErr = fmt.Errorf("failed to read model providers file %s: %w", path, err)
-			return
-		}
-
-		var root struct {
-			Providers []ModelProvider `json:"factory_llm_infos"`
-		}
-		if err := json.Unmarshal(data, &root); err != nil {
-			modelProvidersErr = fmt.Errorf("failed to unmarshal model providers JSON: %w", err)
-			return
-		}
-
-		modelProviders = root.Providers
-		// Build name to index map for fast lookup
-		modelProviderMap = make(map[string]int, len(modelProviders))
-		for i, provider := range modelProviders {
-			modelProviderMap[provider.Name] = i
-		}
-	})
-
-	return modelProvidersErr
-}
-
-// GetModelProviders returns the loaded model providers.
-// Call LoadModelProviders first, otherwise returns empty slice.
-func GetModelProviders() []ModelProvider {
-	return modelProviders
-}
-
-// GetModelProviderByName returns the model provider with the given name.
-func GetModelProviderByName(name string) *ModelProvider {
-	if modelProviderMap == nil {
-		return nil
-	}
-	if idx, ok := modelProviderMap[name]; ok {
-		return &modelProviders[idx]
-	}
-	return nil
-}
-
-// GetLLMByProviderAndName returns the LLM with the given provider name and model name.
-func GetLLMByProviderAndName(providerName, modelName string) *LLM {
-	provider := GetModelProviderByName(providerName)
-	if provider == nil {
-		return nil
-	}
-	for i := range provider.LLMs {
-		if provider.LLMs[i].LLMName == modelName {
-			return &provider.LLMs[i]
-		}
-	}
-	return nil
-}