feat(EE): AI vector search (#1691)

* WIP

* AI module - init

* WIP

* sync

* WIP

* refactor naming

* new columns

* sync

* sync

* fix search bug

* stream response

* WIP

* feat embeddings sync

* refine

* Add workspaceId to page events

* refine

* WIP

* add translation string

* sync

* reset ai answer on query change

* hide AI search in cloud

* capture streaming error

* sync

apps/server/src/database/helpers/helpers.ts

@@ -0,0 +1,22 @@
+import { sql } from 'kysely';
+import { KyselyDB } from '@docmost/db/types/kysely.types';
+
+export async function isPageEmbeddingsTableExists(db: KyselyDB) {
+  return tableExists({ db, tableName: 'page_embeddings' });
+}
+
+export async function tableExists(opts: {
+  db: KyselyDB;
+  tableName: string;
+}): Promise<boolean> {
+  const { db, tableName } = opts;
+  const result = await sql<{ exists: boolean }>`
+      SELECT EXISTS (
+        SELECT 1 FROM information_schema.tables
+        WHERE table_schema = COALESCE(current_schema(), 'public')
+        AND table_name = ${tableName}
+      ) as exists
+    `.execute(db);
+
+  return result.rows[0]?.exists ?? false;
+}