feat(admin): 新增管理后台模型渠道配置功能

- 实现了管理后台模型渠道的增删改查功能
- 将前端直接调用API改为通过后端接口代理获取模型列表
- 添加了渠道测试连接和模型可用性检测功能
- 实现了API Key安全存储机制，前端不再明文显示
- 更新了管理后台设置页面的渠道配置界面
- 添加了表格选中行背景色主题配置支持
- 重构了错误处理机制，统一返回安全错误信息
- 整理了后端模型代理路径为OpenAI风格的/api/v1/*

handler/response.go

@@ -25,6 +25,10 @@ func Fail(w http.ResponseWriter, msg string) {
 
 func FailError(w http.ResponseWriter, err error) {
 	log.Printf("request failed: %v", err)
+	if safe, ok := err.(interface{ SafeMessage() string }); ok {
+		Fail(w, safe.SafeMessage())
+		return
+	}
 	Fail(w, "操作失败")
 }
 

handler/settings.go

@@ -8,6 +8,12 @@ import (
 	"github.com/basketikun/infinite-canvas/service"
 )
 
+type adminChannelActionRequest struct {
+	Index   *int               `json:"index"`
+	Channel model.ModelChannel `json:"channel"`
+	Model   string             `json:"model"`
+}
+
 func Settings(w http.ResponseWriter, r *http.Request) {
 	settings, err := service.PublicSettings()
 	if err != nil {
@@ -36,3 +42,25 @@ func AdminSaveSettings(w http.ResponseWriter, r *http.Request) {
 	}
 	OK(w, result)
 }
+
+func AdminChannelModels(w http.ResponseWriter, r *http.Request) {
+	var request adminChannelActionRequest
+	_ = json.NewDecoder(r.Body).Decode(&request)
+	models, err := service.AdminChannelModels(request.Index, request.Channel)
+	if err != nil {
+		FailError(w, err)
+		return
+	}
+	OK(w, models)
+}
+
+func AdminTestChannelModel(w http.ResponseWriter, r *http.Request) {
+	var request adminChannelActionRequest
+	_ = json.NewDecoder(r.Body).Decode(&request)
+	result, err := service.AdminTestChannelModel(request.Index, request.Channel, request.Model)
+	if err != nil {
+		FailError(w, err)
+		return
+	}
+	OK(w, result)
+}