feat: label AI-generated conversation messages

packages/api-contracts/src/chats.ts

@@ -13,6 +13,7 @@ export const ChatMessageSchema = z.strictObject({
   text: z.string(),
   timestamp: z.number(),
   isSelf: z.boolean(),
+  isAi: z.boolean().optional(),
   media: z.array(ChatMediaSchema).optional(),
 });
 export const ActiveChatSchema = z.strictObject({