feat(ui): add endpoint format hint for Codex providers

Add informational hint below Codex API endpoint input field to guide users
to fill in OpenAI Response compatible service endpoints, similar to the
existing hint for Claude providers.

src/components/ProviderForm.tsx

@@ -1774,6 +1774,11 @@ const ProviderForm: React.FC<ProviderFormProps> = ({
                   autoComplete="off"
                   className="w-full px-3 py-2 border border-gray-200 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-100 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-blue-500/20 dark:focus:ring-blue-400/20 focus:border-blue-500 dark:focus:border-blue-400 transition-colors"
                 />
+                <div className="p-3 bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-700 rounded-lg">
+                  <p className="text-xs text-amber-600 dark:text-amber-400">
+                    {t("providerForm.codexApiHint")}
+                  </p>
+                </div>
               </div>
             )}
 

src/i18n/locales/en.json

@@ -174,6 +174,7 @@
     "fastModelPlaceholder": "e.g., GLM-4.5-Air",
     "modelHint": "💡 Leave blank to use provider's default model",
     "apiHint": "💡 Fill in Claude API compatible service endpoint",
+    "codexApiHint": "💡 Fill in service endpoint compatible with OpenAI Response format",
     "fillSupplierName": "Please fill in provider name",
     "fillConfigContent": "Please fill in configuration content",
     "fillParameter": "Please fill in {{label}}",

src/i18n/locales/zh.json

@@ -174,6 +174,7 @@
     "fastModelPlaceholder": "例如: GLM-4.5-Air",
     "modelHint": "💡 留空将使用供应商的默认模型",
     "apiHint": "💡 填写兼容 Claude API 的服务端点地址",
+    "codexApiHint": "💡 填写兼容 OpenAI Response 格式的服务端点地址",
     "fillSupplierName": "请填写供应商名称",
     "fillConfigContent": "请填写配置内容",
     "fillParameter": "请填写 {{label}}",