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

model/casbin_rule.go

@@ -0,0 +1,16 @@
+package model
+
+type CasbinRule struct {
+	Id    uint   `gorm:"primaryKey;autoIncrement"`
+	Ptype string `gorm:"size:100;index:idx_casbin_rule,priority:1;uniqueIndex:idx_casbin_rule_unique,priority:1"`
+	V0    string `gorm:"size:100;index:idx_casbin_rule,priority:2;uniqueIndex:idx_casbin_rule_unique,priority:2"`
+	V1    string `gorm:"size:100;index:idx_casbin_rule,priority:3;uniqueIndex:idx_casbin_rule_unique,priority:3"`
+	V2    string `gorm:"size:100;index:idx_casbin_rule,priority:4;uniqueIndex:idx_casbin_rule_unique,priority:4"`
+	V3    string `gorm:"size:100;index:idx_casbin_rule,priority:5;uniqueIndex:idx_casbin_rule_unique,priority:5"`
+	V4    string `gorm:"size:100;index:idx_casbin_rule,priority:6;uniqueIndex:idx_casbin_rule_unique,priority:6"`
+	V5    string `gorm:"size:100;index:idx_casbin_rule,priority:7;uniqueIndex:idx_casbin_rule_unique,priority:7"`
+}
+
+func (CasbinRule) TableName() string {
+	return "casbin_rule"
+}