Add canvas interface (#461)

ai/models.ts

@@ -0,0 +1,31 @@
+// Define your models here.
+
+export interface Model {
+  id: string;
+  label: string;
+  apiIdentifier: string;
+  description: string;
+}
+
+export const models: Array<Model> = [
+  {
+    id: 'gpt-4o-mini',
+    label: 'GPT 4o mini',
+    apiIdentifier: 'gpt-4o-mini',
+    description: 'Small model for fast, lightweight tasks',
+  },
+  {
+    id: 'gpt-4o',
+    label: 'GPT 4o',
+    apiIdentifier: 'gpt-4o',
+    description: 'For complex, multi-step tasks',
+  },
+  {
+    id: 'gpt-4o-canvas',
+    label: 'GPT 4o with Canvas',
+    apiIdentifier: 'gpt-4o',
+    description: 'Collaborate with writing',
+  },
+] as const;
+
+export const DEFAULT_MODEL_NAME: string = 'gpt-4o-mini';