refactor: remove resolveOpenAIUpstreamModel, use normalizeCodexModel directly

Eliminates unnecessary indirection layer. The wrapper function only
called normalizeCodexModel with a special case for "gpt 5.3 codex spark"
(space-separated variant) that is no longer needed.

All call sites now use normalizeCodexModel directly.

backend/internal/service/openai_compat_prompt_cache_key.go

@@ -10,8 +10,8 @@ import (
 const compatPromptCacheKeyPrefix = "compat_cc_"
 
 func shouldAutoInjectPromptCacheKeyForCompat(model string) bool {
-	switch resolveOpenAIUpstreamModel(strings.TrimSpace(model)) {
-	case "gpt-5.4", "gpt-5.3-codex", "gpt-5.3-codex-spark":
+	switch normalizeCodexModel(strings.TrimSpace(model)) {
+	case "gpt-5.4", "gpt-5.3-codex":
 		return true
 	default:
 		return false
@@ -23,9 +23,9 @@ func deriveCompatPromptCacheKey(req *apicompat.ChatCompletionsRequest, mappedMod
 		return ""
 	}
 
-	normalizedModel := resolveOpenAIUpstreamModel(strings.TrimSpace(mappedModel))
+	normalizedModel := normalizeCodexModel(strings.TrimSpace(mappedModel))
 	if normalizedModel == "" {
-		normalizedModel = resolveOpenAIUpstreamModel(strings.TrimSpace(req.Model))
+		normalizedModel = normalizeCodexModel(strings.TrimSpace(req.Model))
 	}
 	if normalizedModel == "" {
 		normalizedModel = strings.TrimSpace(req.Model)

backend/internal/service/openai_gateway_chat_completions.go

@@ -46,7 +46,7 @@ func (s *OpenAIGatewayService) ForwardAsChatCompletions(
 	// 2. Resolve model mapping early so compat prompt_cache_key injection can
 	// derive a stable seed from the final upstream model family.
 	billingModel := resolveOpenAIForwardModel(account, originalModel, defaultMappedModel)
-	upstreamModel := resolveOpenAIUpstreamModel(billingModel)
+	upstreamModel := normalizeCodexModel(billingModel)
 
 	promptCacheKey = strings.TrimSpace(promptCacheKey)
 	compatPromptCacheInjected := false

backend/internal/service/openai_gateway_messages.go

@@ -62,7 +62,7 @@ func (s *OpenAIGatewayService) ForwardAsAnthropic(
 
 	// 3. Model mapping
 	billingModel := resolveOpenAIForwardModel(account, normalizedModel, defaultMappedModel)
-	upstreamModel := resolveOpenAIUpstreamModel(billingModel)
+	upstreamModel := normalizeCodexModel(billingModel)
 	responsesReq.Model = upstreamModel
 
 	logger.L().Debug("openai messages: model mapping applied",

backend/internal/service/openai_gateway_service.go

@@ -1939,7 +1939,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 
 	// 针对所有 OpenAI 账号执行 Codex 模型名规范化，确保上游识别一致。
 	if model, ok := reqBody["model"].(string); ok {
-		upstreamModel = resolveOpenAIUpstreamModel(model)
+		upstreamModel = normalizeCodexModel(model)
 		if upstreamModel != "" && upstreamModel != model {
 			logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Upstream model resolved: %s -> %s (account: %s, type: %s, isCodexCLI: %v)",
 				model, upstreamModel, account.Name, account.Type, isCodexCLI)

backend/internal/service/openai_model_mapping.go

@@ -1,10 +1,8 @@
 package service
 
-import "strings"
-
-// resolveOpenAIForwardModel resolves the account/group mapping result for
-// OpenAI-compatible forwarding. Group-level default mapping only applies when
-// the account itself did not match any explicit model_mapping rule.
+// resolveOpenAIForwardModel determines the upstream model for OpenAI-compatible
+// forwarding. Group-level default mapping only applies when the account itself
+// did not match any explicit model_mapping rule.
 func resolveOpenAIForwardModel(account *Account, requestedModel, defaultMappedModel string) string {
 	if account == nil {
 		if defaultMappedModel != "" {
@@ -19,23 +17,3 @@ func resolveOpenAIForwardModel(account *Account, requestedModel, defaultMappedMo
 	}
 	return mappedModel
 }
-
-func resolveOpenAIUpstreamModel(model string) string {
-	if isBareGPT53CodexSparkModel(model) {
-		return "gpt-5.3-codex-spark"
-	}
-	return normalizeCodexModel(strings.TrimSpace(model))
-}
-
-func isBareGPT53CodexSparkModel(model string) bool {
-	modelID := strings.TrimSpace(model)
-	if modelID == "" {
-		return false
-	}
-	if strings.Contains(modelID, "/") {
-		parts := strings.Split(modelID, "/")
-		modelID = parts[len(parts)-1]
-	}
-	normalized := strings.ToLower(strings.TrimSpace(modelID))
-	return normalized == "gpt-5.3-codex-spark" || normalized == "gpt 5.3 codex spark"
-}

backend/internal/service/openai_model_mapping_test.go

@@ -74,30 +74,28 @@ func TestResolveOpenAIForwardModel_PreventsClaudeModelFromFallingBackToGpt51(t *
 		Credentials: map[string]any{},
 	}
 
-	withoutDefault := resolveOpenAIUpstreamModel(resolveOpenAIForwardModel(account, "claude-opus-4-6", ""))
+	withoutDefault := normalizeCodexModel(resolveOpenAIForwardModel(account, "claude-opus-4-6", ""))
 	if withoutDefault != "gpt-5.1" {
-		t.Fatalf("resolveOpenAIUpstreamModel(...) = %q, want %q", withoutDefault, "gpt-5.1")
+		t.Fatalf("normalizeCodexModel(...) = %q, want %q", withoutDefault, "gpt-5.1")
 	}
 
-	withDefault := resolveOpenAIUpstreamModel(resolveOpenAIForwardModel(account, "claude-opus-4-6", "gpt-5.4"))
+	withDefault := normalizeCodexModel(resolveOpenAIForwardModel(account, "claude-opus-4-6", "gpt-5.4"))
 	if withDefault != "gpt-5.4" {
-		t.Fatalf("resolveOpenAIUpstreamModel(...) = %q, want %q", withDefault, "gpt-5.4")
+		t.Fatalf("normalizeCodexModel(...) = %q, want %q", withDefault, "gpt-5.4")
 	}
 }
 
-func TestResolveOpenAIUpstreamModel(t *testing.T) {
+func TestNormalizeCodexModel(t *testing.T) {
 	cases := map[string]string{
-		"gpt-5.3-codex-spark":          "gpt-5.3-codex-spark",
-		"gpt 5.3 codex spark":          "gpt-5.3-codex-spark",
-		" openai/gpt-5.3-codex-spark ": "gpt-5.3-codex-spark",
+		"gpt-5.3-codex-spark":          "gpt-5.3-codex",
 		"gpt-5.3-codex-spark-high":     "gpt-5.3-codex",
 		"gpt-5.3-codex-spark-xhigh":    "gpt-5.3-codex",
 		"gpt-5.3":                      "gpt-5.3-codex",
 	}
 
 	for input, expected := range cases {
-		if got := resolveOpenAIUpstreamModel(input); got != expected {
-			t.Fatalf("resolveOpenAIUpstreamModel(%q) = %q, want %q", input, got, expected)
+		if got := normalizeCodexModel(input); got != expected {
+			t.Fatalf("normalizeCodexModel(%q) = %q, want %q", input, got, expected)
 		}
 	}
 }

backend/internal/service/openai_ws_forwarder.go

@@ -2515,7 +2515,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 			}
 			normalized = next
 		}
-		upstreamModel := resolveOpenAIUpstreamModel(account.GetMappedModel(originalModel))
+		upstreamModel := normalizeCodexModel(account.GetMappedModel(originalModel))
 		if upstreamModel != originalModel {
 			next, setErr := applyPayloadMutation(normalized, "model", upstreamModel)
 			if setErr != nil {
@@ -2773,7 +2773,7 @@ func (s *OpenAIGatewayService) ProxyResponsesWebSocketFromClient(
 		mappedModel := ""
 		var mappedModelBytes []byte
 		if originalModel != "" {
-			mappedModel = resolveOpenAIUpstreamModel(account.GetMappedModel(originalModel))
+			mappedModel = normalizeCodexModel(account.GetMappedModel(originalModel))
 			needModelReplace = mappedModel != "" && mappedModel != originalModel
 			if needModelReplace {
 				mappedModelBytes = []byte(mappedModel)