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

setting/perf_metrics_setting/config.go

@@ -0,0 +1,45 @@
+package perf_metrics_setting
+
+import "github.com/QuantumNous/new-api/setting/config"
+
+type PerfMetricsSetting struct {
+	Enabled       bool   `json:"enabled"`
+	FlushInterval int    `json:"flush_interval"`
+	BucketTime    string `json:"bucket_time"`
+	RetentionDays int    `json:"retention_days"`
+}
+
+var perfMetricsSetting = PerfMetricsSetting{
+	Enabled:       true,
+	FlushInterval: 5,
+	BucketTime:    "hour",
+	RetentionDays: 0,
+}
+
+func init() {
+	config.GlobalConfig.Register("perf_metrics_setting", &perfMetricsSetting)
+}
+
+func GetSetting() PerfMetricsSetting {
+	return perfMetricsSetting
+}
+
+func GetBucketSeconds() int64 {
+	switch perfMetricsSetting.BucketTime {
+	case "minute":
+		return 60
+	case "5min":
+		return 300
+	case "hour":
+		return 3600
+	default:
+		return 3600
+	}
+}
+
+func GetFlushIntervalMinutes() int {
+	if perfMetricsSetting.FlushInterval < 1 {
+		return 1
+	}
+	return perfMetricsSetting.FlushInterval
+}