feat(36-01): add isAdmin column to users table schema and generate migration

- Add isAdmin boolean(is_admin) NOT NULL DEFAULT false to users table
- Generate migration 0009_spotty_lord_tyger.sql
- NOTE: db:push requires DATABASE_URL with correct credentials to apply

drizzle-pg/0009_spotty_lord_tyger.sql

@@ -0,0 +1 @@
+ALTER TABLE "users" ADD COLUMN "is_admin" boolean DEFAULT false NOT NULL;