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/crypto.go

@@ -0,0 +1,32 @@
+package common
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+func GenerateHMACWithKey(key []byte, data string) string {
+	h := hmac.New(sha256.New, key)
+	h.Write([]byte(data))
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+func GenerateHMAC(data string) string {
+	h := hmac.New(sha256.New, []byte(CryptoSecret))
+	h.Write([]byte(data))
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+func Password2Hash(password string) (string, error) {
+	passwordBytes := []byte(password)
+	hashedPassword, err := bcrypt.GenerateFromPassword(passwordBytes, bcrypt.DefaultCost)
+	return string(hashedPassword), err
+}
+
+func ValidatePasswordAndHash(password string, hash string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+	return err == nil
+}