fix: chat query (#1170)

Co-authored-by: josh <josh@afterima.ge>

lib/db/schema.ts

@@ -4,12 +4,14 @@ import {
   varchar,
   timestamp,
   json,
+  jsonb,
   uuid,
   text,
   primaryKey,
   foreignKey,
   boolean,
 } from 'drizzle-orm/pg-core';
+import type { LanguageModelV2Usage } from '@ai-sdk/provider';
 
 export const user = pgTable('User', {
   id: uuid('id').primaryKey().notNull().defaultRandom(),
@@ -29,6 +31,7 @@ export const chat = pgTable('Chat', {
   visibility: varchar('visibility', { enum: ['public', 'private'] })
     .notNull()
     .default('private'),
+  lastContext: jsonb('lastContext').$type<LanguageModelV2Usage | null>(),
 });
 
 export type Chat = InferSelectModel<typeof chat>;