chore(db): finish Prisma cutover to Drizzle Kit tooling

Move CMS SQL to drizzle/migrations, drop prisma packages/schema, wire drizzle-kit scripts, and regenerate schema names from src/db/schema.ts.

Co-authored-by: Cursor <[email protected]>

drizzle/migrations/0016_housekeeping_group_field.sql

@@ -0,0 +1,6 @@
+ALTER TABLE `website_housekeeping_permissions`
+  ADD COLUMN `group_name` VARCHAR(100) DEFAULT NULL AFTER `description`,
+  ADD COLUMN `depends_on` VARCHAR(255) DEFAULT NULL AFTER `group_name`,
+  ADD COLUMN `updated_by` INT DEFAULT NULL AFTER `updated_at`;
+
+-- Migration tracking (no model change needed for audit log usage)