Vision model support for Qwen-OAuth (#525)

* refactor: openaiContentGenerator

* refactor: optimize stream handling

* refactor: re-organize refactored files

* fix: unit test cases

* feat: `/model` command for switching to vision model

* fix: lint error

* feat: add image tokenizer to fit vlm context window

* fix: lint and type errors

* feat: add `visionModelPreview` to control default visibility of vision models

* fix: remove deprecated files

* fix: align supported image formats with bailian doc

packages/cli/src/ui/models/availableModels.ts

@@ -0,0 +1,52 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export type AvailableModel = {
+  id: string;
+  label: string;
+  isVision?: boolean;
+};
+
+export const AVAILABLE_MODELS_QWEN: AvailableModel[] = [
+  { id: 'qwen3-coder-plus', label: 'qwen3-coder-plus' },
+  { id: 'qwen-vl-max-latest', label: 'qwen-vl-max', isVision: true },
+];
+
+/**
+ * Get available Qwen models filtered by vision model preview setting
+ */
+export function getFilteredQwenModels(
+  visionModelPreviewEnabled: boolean,
+): AvailableModel[] {
+  if (visionModelPreviewEnabled) {
+    return AVAILABLE_MODELS_QWEN;
+  }
+  return AVAILABLE_MODELS_QWEN.filter((model) => !model.isVision);
+}
+
+/**
+ * Currently we use the single model of `OPENAI_MODEL` in the env.
+ * In the future, after settings.json is updated, we will allow users to configure this themselves.
+ */
+export function getOpenAIAvailableModelFromEnv(): AvailableModel | null {
+  const id = process.env['OPENAI_MODEL']?.trim();
+  return id ? { id, label: id } : null;
+}
+
+/**
+/**
+ * Hard code the default vision model as a string literal,
+ * until our coding model supports multimodal.
+ */
+export function getDefaultVisionModel(): string {
+  return 'qwen-vl-max-latest';
+}
+
+export function isVisionModel(modelId: string): boolean {
+  return AVAILABLE_MODELS_QWEN.some(
+    (model) => model.id === modelId && model.isVision,
+  );
+}