feat: add preset aliyun qwen model switching

src/lib/ai-account-models.ts

@@ -0,0 +1,19 @@
+export const ALIYUN_QWEN_PRESET_MODELS = ["qwen3.5-plus", "qwen3.5-flash"] as const;
+
+export const ALIYUN_QWEN_CUSTOM_MODEL_VALUE = "__custom__";
+
+export function isAliyunQwenPresetModel(model: string | null | undefined) {
+  const trimmed = model?.trim() ?? "";
+  return ALIYUN_QWEN_PRESET_MODELS.includes(trimmed as (typeof ALIYUN_QWEN_PRESET_MODELS)[number]);
+}
+
+export function resolveAliyunQwenModelSelection(model: string | null | undefined) {
+  return isAliyunQwenPresetModel(model) ? (model?.trim() ?? "") : ALIYUN_QWEN_CUSTOM_MODEL_VALUE;
+}
+
+export function resolveAliyunQwenModelValue(selection: string, customModel: string) {
+  if (selection === ALIYUN_QWEN_CUSTOM_MODEL_VALUE) {
+    return customModel.trim();
+  }
+  return selection.trim();
+}