feat(codex): decouple upstream format selector from model-mapping toggle

The Codex provider form tied Chat-format conversion and route takeover (model
mapping) to one toggle, so a provider serving a native Responses API could not
use model mapping without forcing Chat Completions conversion.

- Promote the upstream format (Chat Completions / Responses) to an independent,
  always-visible selector that triggers no sub-menus on its own.
- The local-routing toggle now solely gates the advanced sub-sections: model
  mapping catalog, plus reasoning capability when the format is Chat.
- Persist modelCatalog / codexChatReasoning based on the takeover toggle and
  derive its initial state from saved catalog presence (no new persisted field).
- Refresh codexConfig i18n (zh/en/ja/zh-TW): add upstreamFormat* keys and reword
  the routing/advanced hints to reflect the decoupling.
- Fix codexChatProviderPresets test expectation for the Doubao Seed 2.1 Pro rename.

src/components/providers/forms/CodexFormFields.tsx

@@ -4,6 +4,13 @@ import { Button } from "@/components/ui/button";
 import { FormLabel } from "@/components/ui/form";
 import { Input } from "@/components/ui/input";
 import { Switch } from "@/components/ui/switch";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
 import {
   Collapsible,
   CollapsibleContent,
@@ -62,6 +69,13 @@ interface CodexFormFieldsProps {
   autoSelect: boolean;
   onAutoSelectChange: (checked: boolean) => void;
 
+  // Local routing / takeover
+  // takeoverEnabled gates model mapping + reasoning visibility; it is decoupled
+  // from the wire format so a native Responses provider can use model mapping
+  // without Chat Completions conversion.
+  takeoverEnabled: boolean;
+  onTakeoverEnabledChange: (enabled: boolean) => void;
+
   // API Format
   // Note: wire_api is always "responses" for Codex; apiFormat controls proxy-layer conversion
   apiFormat: CodexApiFormat;
@@ -132,6 +146,8 @@ export function CodexFormFields({
   onCustomEndpointsChange,
   autoSelect,
   onAutoSelectChange,
+  takeoverEnabled,
+  onTakeoverEnabledChange,
   apiFormat,
   onApiFormatChange,
   codexChatReasoning = {},
@@ -150,7 +166,9 @@ export function CodexFormFields({
 
   const [fetchedModels, setFetchedModels] = useState<FetchedModel[]>([]);
   const [isFetchingModels, setIsFetchingModels] = useState(false);
-  const needsLocalRouting = apiFormat === "openai_chat";
+  // takeoverEnabled 控制模型映射/思考能力的显示；isChatFormat 仅在选了
+  // Chat Completions 上游格式时为真（思考能力是 Chat 专属）。
+  const isChatFormat = apiFormat === "openai_chat";
   const canEditCatalog = Boolean(onCatalogModelsChange);
   const canEditReasoning = Boolean(onCodexChatReasoningChange);
   const supportsThinking =
@@ -158,12 +176,13 @@ export function CodexFormFields({
     codexChatReasoning.supportsEffort === true;
   const supportsEffort = codexChatReasoning.supportsEffort === true;
 
-  // needsLocalRouting 非默认值说明预设/用户动过路由配置，需要让模型映射保持可见
+  // takeoverEnabled 取代了旧的 needsLocalRouting：上游格式已与路由解耦。
+  // takeoverEnabled 为真说明预设/用户启用了本地路由；请求头/请求体覆盖也算高级值。
   const hasRequestOverrides = Boolean(
     localProxyHeadersOverride.trim() || localProxyBodyOverride.trim(),
   );
   const hasAnyAdvancedValue =
-    !!customUserAgent || hasRequestOverrides || needsLocalRouting;
+    !!customUserAgent || hasRequestOverrides || takeoverEnabled;
   const [advancedExpanded, setAdvancedExpanded] = useState(hasAnyAdvancedValue);
 
   // 预设/编辑加载填充高级值后自动展开（仅从折叠→展开，不会自动折叠）
@@ -204,13 +223,6 @@ export function CodexFormFields({
     onCatalogModelsChange(next);
   }, [catalogRows, onCatalogModelsChange]);
 
-  const handleLocalRoutingChange = useCallback(
-    (checked: boolean) => {
-      onApiFormatChange(checked ? "openai_chat" : "openai_responses");
-    },
-    [onApiFormatChange],
-  );
-
   const handleReasoningThinkingChange = useCallback(
     (checked: boolean) => {
       if (!onCodexChatReasoningChange) return;
@@ -391,38 +403,83 @@ export function CodexFormFields({
             </p>
           )}
           <CollapsibleContent className="space-y-3 pt-3">
-            {/* 本地路由映射开关 —— 沿用 shouldShowSpeedTest 门控，cloud_provider 保持不可切换 */}
+            {/* 上游格式 + 本地路由映射 —— 两个平级、相互独立的控件。
+                格式不依赖路由：Responses 原生供应商无需开启路由即可直连；
+                沿用 shouldShowSpeedTest 门控，cloud_provider 保持不可切换。 */}
             {shouldShowSpeedTest && (
-              <div className="flex items-center justify-between gap-4">
-                <div className="space-y-1">
-                  <FormLabel>
-                    {t("codexConfig.localRoutingToggle", {
-                      defaultValue: "需要本地路由映射",
+              <div className="space-y-3">
+                {/* 上游格式 —— 顶层独立选择，与路由开关解耦 */}
+                <div className="space-y-1.5">
+                  <FormLabel htmlFor="codex-upstream-format">
+                    {t("codexConfig.upstreamFormatLabel", {
+                      defaultValue: "上游格式",
                     })}
                   </FormLabel>
-                  <p className="text-xs leading-relaxed text-muted-foreground">
-                    {needsLocalRouting
-                      ? t("codexConfig.localRoutingOnHint", {
-                          defaultValue:
-                            "Codex 目前仅原生支持 OpenAI Responses API 与 GPT 系列模型；如果您的供应商使用 Chat Completions 协议或非 GPT 模型（如 DeepSeek、Kimi），则需要打开本开关，并在使用过程中保持本地路由开启。",
-                        })
-                      : t("codexConfig.localRoutingOffHint", {
-                          defaultValue:
-                            "如果您的供应商不是原生 OpenAI Responses API，或者模型名不是 Codex 默认的 GPT 系列，请打开此开关。",
+                  <Select
+                    value={apiFormat}
+                    onValueChange={(value) =>
+                      onApiFormatChange(value as CodexApiFormat)
+                    }
+                  >
+                    <SelectTrigger
+                      id="codex-upstream-format"
+                      className="w-full"
+                    >
+                      <SelectValue />
+                    </SelectTrigger>
+                    <SelectContent>
+                      <SelectItem value="openai_chat">
+                        {t("codexConfig.upstreamFormatChat", {
+                          defaultValue: "Chat Completions（转换）",
                         })}
+                      </SelectItem>
+                      <SelectItem value="openai_responses">
+                        {t("codexConfig.upstreamFormatResponses", {
+                          defaultValue: "Responses（原生）",
+                        })}
+                      </SelectItem>
+                    </SelectContent>
+                  </Select>
+                  <p className="text-xs leading-relaxed text-muted-foreground">
+                    {t("codexConfig.upstreamFormatHint", {
+                      defaultValue:
+                        "供应商原生是 Responses API 就选 Responses（直连，不转换格式）；使用 Chat Completions 协议就选 Chat（转换为 Chat Completions）。",
+                    })}
                   </p>
                 </div>
-                <Switch
-                  checked={needsLocalRouting}
-                  onCheckedChange={handleLocalRoutingChange}
-                  aria-label={t("codexConfig.localRoutingToggle", {
-                    defaultValue: "需要本地路由映射",
-                  })}
-                />
+
+                {/* 需要本地路由映射 —— 纯模型映射门控，与上游格式无关 */}
+                <div className="flex items-center justify-between gap-4 border-t border-border-default pt-3">
+                  <div className="space-y-1">
+                    <FormLabel>
+                      {t("codexConfig.localRoutingToggle", {
+                        defaultValue: "需要本地路由映射",
+                      })}
+                    </FormLabel>
+                    <p className="text-xs leading-relaxed text-muted-foreground">
+                      {takeoverEnabled
+                        ? t("codexConfig.localRoutingOnHint", {
+                            defaultValue:
+                              "打开后可在下方配置模型映射：让 Codex 的 /model 菜单显示自定义模型名，并把请求映射到真实上游模型。",
+                          })
+                        : t("codexConfig.localRoutingOffHint", {
+                            defaultValue:
+                              "供应商模型名无需改写、也无需在 /model 菜单展示自定义名称时，可保持关闭；需要模型映射时打开。",
+                          })}
+                    </p>
+                  </div>
+                  <Switch
+                    checked={takeoverEnabled}
+                    onCheckedChange={onTakeoverEnabledChange}
+                    aria-label={t("codexConfig.localRoutingToggle", {
+                      defaultValue: "需要本地路由映射",
+                    })}
+                  />
+                </div>
               </div>
             )}
 
-            {needsLocalRouting && canEditReasoning && (
+            {takeoverEnabled && isChatFormat && canEditReasoning && (
               <div
                 className={cn(
                   "space-y-3",
@@ -495,7 +552,7 @@ export function CodexFormFields({
               className={cn(
                 "space-y-3",
                 (shouldShowSpeedTest ||
-                  (needsLocalRouting && canEditReasoning)) &&
+                  (takeoverEnabled && isChatFormat && canEditReasoning)) &&
                   "border-t border-border-default pt-3",
               )}
             >
@@ -514,8 +571,9 @@ export function CodexFormFields({
               </div>
             </div>
 
-            {/* 模型映射 —— 仅在本地路由 + 可编辑时显示；上方恒有 UA 字段，分隔线无需条件 */}
-            {needsLocalRouting && canEditCatalog && (
+            {/* 模型映射 —— 仅在本地路由开启 + 可编辑时显示（与上游格式解耦，
+                Responses 原生供应商同样可配置）；上方恒有 UA 字段，分隔线无需条件 */}
+            {takeoverEnabled && canEditCatalog && (
               <div className="space-y-4 border-t border-border-default pt-3">
                 <div className="space-y-1">
                   <div className="flex items-center justify-between gap-3">

src/components/providers/forms/ProviderForm.tsx

@@ -150,6 +150,16 @@ const codexApiFormatFromWireApi = (
   }
 };
 
+// 从已保存的 settingsConfig 推断 Codex 模型映射条目数（用于决定本地路由初始开关）。
+const codexCatalogCountFromSettings = (settingsConfig: unknown): number => {
+  if (settingsConfig && typeof settingsConfig === "object") {
+    const models = (settingsConfig as { modelCatalog?: { models?: unknown } })
+      .modelCatalog?.models;
+    return Array.isArray(models) ? models.length : 0;
+  }
+  return 0;
+};
+
 export const normalizeCodexCatalogModelsForSave = (
   models: CodexCatalogModel[],
 ): CodexCatalogModel[] => {
@@ -568,24 +578,29 @@ function ProviderFormFull({
     resetCodexConfig,
   } = useCodexConfigState({ initialData });
 
+  const initialCodexApiFormat: CodexApiFormat =
+    initialData?.meta?.apiFormat === "openai_chat"
+      ? "openai_chat"
+      : initialData?.meta?.apiFormat === "openai_responses"
+        ? "openai_responses"
+        : (codexApiFormatFromWireApi(
+            extractCodexWireApi(
+              typeof initialData?.settingsConfig?.config === "string"
+                ? initialData.settingsConfig.config
+                : "",
+            ),
+          ) ?? "openai_responses");
+
   const [localCodexApiFormat, setLocalCodexApiFormat] =
-    useState<CodexApiFormat>(() => {
-      if (initialData?.meta?.apiFormat === "openai_chat") {
-        return "openai_chat";
-      }
-      if (initialData?.meta?.apiFormat === "openai_responses") {
-        return "openai_responses";
-      }
-      return (
-        codexApiFormatFromWireApi(
-          extractCodexWireApi(
-            typeof initialData?.settingsConfig?.config === "string"
-              ? initialData.settingsConfig.config
-              : "",
-          ),
-        ) ?? "openai_responses"
-      );
-    });
+    useState<CodexApiFormat>(initialCodexApiFormat);
+
+  // 本地路由（接管）开关 —— 纯模型映射门控，与上游格式完全独立。
+  // 没有独立持久化字段，初值仅按「是否已配置模型映射」推断（有 catalog 即视为
+  // 接管已开）。只在 useState 初始化与预设重置点设置，跟 localCodexApiFormat
+  // 对称，避免漂移。
+  const [codexTakeoverEnabled, setCodexTakeoverEnabled] = useState<boolean>(
+    () => codexCatalogCountFromSettings(initialData?.settingsConfig) > 0,
+  );
 
   const { configError: codexConfigError, debouncedValidate } =
     useCodexTomlValidation();
@@ -616,6 +631,7 @@ function ProviderFormFull({
       const template = getCodexCustomTemplate();
       resetCodexConfig(template.auth, template.config);
       setCodexChatReasoning({});
+      setCodexTakeoverEnabled(false);
     }
   }, [appId, initialData, selectedPresetId, resetCodexConfig]);
 
@@ -1262,7 +1278,7 @@ function ProviderFormFull({
             ? setCodexWireApi(codexConfig ?? "", "responses")
             : (codexConfig ?? "");
         const normalizedCatalogModels =
-          category !== "official" && localCodexApiFormat === "openai_chat"
+          category !== "official" && codexTakeoverEnabled
             ? normalizeCodexCatalogModelsForSave(codexCatalogModels)
             : [];
         // Sync first catalog row's model into config.toml so Codex uses it as default
@@ -1458,6 +1474,7 @@ function ProviderFormFull({
       codexChatReasoning:
         appId === "codex" &&
         category !== "official" &&
+        codexTakeoverEnabled &&
         localCodexApiFormat === "openai_chat"
           ? normalizeCodexChatReasoningForSave(codexChatReasoning)
           : undefined,
@@ -1610,6 +1627,8 @@ function ProviderFormFull({
           codexApiFormatFromWireApi(extractCodexWireApi(template.config)) ??
             "openai_responses",
         );
+        // 自定义模板无模型映射，路由默认关闭
+        setCodexTakeoverEnabled(false);
       }
       if (appId === "gemini") {
         resetGeminiConfig({}, {});
@@ -1652,6 +1671,8 @@ function ProviderFormFull({
           codexApiFormatFromWireApi(extractCodexWireApi(config)) ??
           "openai_responses",
       );
+      // 路由开关与格式无关，仅按预设是否带模型映射决定
+      setCodexTakeoverEnabled((preset.modelCatalog?.length ?? 0) > 0);
 
       form.reset({
         name: preset.nameKey ? t(preset.nameKey) : preset.name,
@@ -2124,6 +2145,8 @@ function ProviderFormFull({
               }
               autoSelect={endpointAutoSelect}
               onAutoSelectChange={setEndpointAutoSelect}
+              takeoverEnabled={codexTakeoverEnabled}
+              onTakeoverEnabledChange={setCodexTakeoverEnabled}
               apiFormat={localCodexApiFormat}
               onApiFormatChange={handleCodexApiFormatChange}
               codexChatReasoning={codexChatReasoning}