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]>

src/db/schema.ts

@@ -1,6 +1,6 @@
 // AUTO-GENERATED by scripts/generate-drizzle-schema.mjs — DO NOT EDIT.
-// TS field names mirror prisma/schema.prisma (camelCase); column names are the
-// real MySQL columns. Run `pnpm db:schema:generate` after schema changes.
+// TS field names come from the previous src/db/schema.ts; column types from the
+// live MySQL DB. Run `pnpm db:schema:generate` after schema/map changes.
 
 import { sql } from "drizzle-orm";
 import {