Rebuild atomcms-next foundation on Prisma (align to habbo-next reference)

Replace the superseded Drizzle monorepo scaffold with a single-app Prisma 7
data layer, mirroring the proven habbo-next approach to the shared Arcturus
emulator DB (introspect/conform only, idempotent SQL migrations via a custom
runner; never migrate-diff).

- prisma/schema.prisma: User, UsersCurrency (composite PK), Ban, WebsiteSetting
  mapped to AtomCMS's default.sql columns; client generated to src/generated/prisma
- src/lib/prisma.ts: PrismaMariaDb adapter singleton; src/env.ts zod env
- src/lib/services: siteSettings (cached setting() equivalent) + CurrencyType enum
- prisma/migrations + scripts/apply-migrations.ts: idempotent CMS-table runner

Verified: prisma generate OK, tsc --noEmit exit 0, vitest 6/6 pass.

src/lib/services/currency.ts

@@ -0,0 +1,18 @@
+// Numeric values are dictated by the Arcturus emulator and MUST NOT change.
+export enum CurrencyType {
+  Credits = -1,
+  Duckets = 0,
+  Diamonds = 5,
+  Points = 101,
+}
+
+const LABELS: Record<CurrencyType, string> = {
+  [CurrencyType.Credits]: "Credits",
+  [CurrencyType.Duckets]: "Duckets",
+  [CurrencyType.Diamonds]: "Diamonds",
+  [CurrencyType.Points]: "Points",
+};
+
+export function currencyLabel(type: CurrencyType): string {
+  return LABELS[type];
+}