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/model.go

@@ -0,0 +1,59 @@
+package common
+
+import "strings"
+
+var (
+	// OpenAIResponseOnlyModels is a list of models that are only available for OpenAI responses.
+	OpenAIResponseOnlyModels = []string{
+		"o3-pro",
+		"o3-deep-research",
+		"o4-mini-deep-research",
+	}
+	ImageGenerationModels = []string{
+		"dall-e-3",
+		"dall-e-2",
+		"gpt-image-1",
+		"prefix:imagen-",
+		"flux-",
+		"flux.1-",
+	}
+	OpenAITextModels = []string{
+		"gpt-",
+		"o1",
+		"o3",
+		"o4",
+		"chatgpt",
+	}
+)
+
+func IsOpenAIResponseOnlyModel(modelName string) bool {
+	for _, m := range OpenAIResponseOnlyModels {
+		if strings.Contains(modelName, m) {
+			return true
+		}
+	}
+	return false
+}
+
+func IsImageGenerationModel(modelName string) bool {
+	modelName = strings.ToLower(modelName)
+	for _, m := range ImageGenerationModels {
+		if strings.Contains(modelName, m) {
+			return true
+		}
+		if strings.HasPrefix(m, "prefix:") && strings.HasPrefix(modelName, strings.TrimPrefix(m, "prefix:")) {
+			return true
+		}
+	}
+	return false
+}
+
+func IsOpenAITextModel(modelName string) bool {
+	modelName = strings.ToLower(modelName)
+	for _, m := range OpenAITextModels {
+		if strings.Contains(modelName, m) {
+			return true
+		}
+	}
+	return false
+}