feat: 算力引擎 Go 后端核心（new-api）

- 统一 OpenAI 兼容 /v1 中继 + 渠道/额度/令牌/流水
- 各领域包：relay 模型网关、model 数据层、controller 管理 API

common/endpoint_defaults.go

@@ -0,0 +1,35 @@
+package common
+
+import "github.com/QuantumNous/new-api/constant"
+
+// EndpointInfo 描述单个端点的默认请求信息
+// path: 上游路径
+// method: HTTP 请求方式，例如 POST/GET
+// 目前均为 POST，后续可扩展
+//
+// json 标签用于直接序列化到 API 输出
+// 例如：{"path":"/v1/chat/completions","method":"POST"}
+
+type EndpointInfo struct {
+	Path   string `json:"path"`
+	Method string `json:"method"`
+}
+
+// defaultEndpointInfoMap 保存内置端点的默认 Path 与 Method
+var defaultEndpointInfoMap = map[constant.EndpointType]EndpointInfo{
+	constant.EndpointTypeOpenAI:                {Path: "/v1/chat/completions", Method: "POST"},
+	constant.EndpointTypeOpenAIResponse:        {Path: "/v1/responses", Method: "POST"},
+	constant.EndpointTypeOpenAIResponseCompact: {Path: "/v1/responses/compact", Method: "POST"},
+	constant.EndpointTypeOpenAIAlphaSearch:     {Path: "/v1/alpha/search", Method: "POST"},
+	constant.EndpointTypeAnthropic:             {Path: "/v1/messages", Method: "POST"},
+	constant.EndpointTypeGemini:                {Path: "/v1beta/models/{model}:generateContent", Method: "POST"},
+	constant.EndpointTypeJinaRerank:            {Path: "/v1/rerank", Method: "POST"},
+	constant.EndpointTypeImageGeneration:       {Path: "/v1/images/generations", Method: "POST"},
+	constant.EndpointTypeEmbeddings:            {Path: "/v1/embeddings", Method: "POST"},
+}
+
+// GetDefaultEndpointInfo 返回指定端点类型的默认信息以及是否存在
+func GetDefaultEndpointInfo(et constant.EndpointType) (EndpointInfo, bool) {
+	info, ok := defaultEndpointInfoMap[et]
+	return info, ok
+}