feat(ee): personal spaces (#2298)

* feat(ee): personal spaces

* pref

* feat: on-demand only

* error notification

apps/server/src/database/migrations/20260620T010047-personal-spaces.ts

@@ -0,0 +1,24 @@
+import { Kysely, sql } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .alterTable('spaces')
+    .addColumn('is_personal', 'boolean', (col) =>
+      col.notNull().defaultTo(false),
+    )
+    .execute();
+
+  await sql`
+    CREATE UNIQUE INDEX spaces_personal_creator_unique
+    ON spaces (creator_id)
+    WHERE is_personal = true AND deleted_at IS NULL
+  `.execute(db);
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .dropIndex('spaces_personal_creator_unique')
+    .ifExists()
+    .execute();
+  await db.schema.alterTable('spaces').dropColumn('is_personal').execute();
+}