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/node_identity.go

@@ -0,0 +1,33 @@
+package common
+
+import "os"
+
+type NodeIdentity struct {
+	Name                    string `json:"name"`
+	Source                  string `json:"source"`
+	ManuallyConfigured      bool   `json:"manually_configured"`
+	ShouldConfigureManually bool   `json:"should_configure_manually"`
+}
+
+func initNodeNameIdentity() {
+	if envNodeName := os.Getenv("NODE_NAME"); envNodeName != "" {
+		NodeName = envNodeName
+		NodeNameSource = NodeNameSourceManual
+		NodeNameManuallyConfigured = true
+		return
+	}
+
+	hostname, _ := os.Hostname()
+	NodeName = hostname
+	NodeNameSource = NodeNameSourceHostname
+	NodeNameManuallyConfigured = false
+}
+
+func GetNodeIdentity() NodeIdentity {
+	return NodeIdentity{
+		Name:                    NodeName,
+		Source:                  NodeNameSource,
+		ManuallyConfigured:      NodeNameManuallyConfigured,
+		ShouldConfigureManually: !NodeNameManuallyConfigured,
+	}
+}