REFACTORED - migrate the data layer from Prisma to Drizzle (unify the stack)

- Add lib/db (Drizzle schema: 7 tables + 6 enums + relations, postgres.js client),
  drizzle.config.ts, lib/db/enums.ts (Prisma-compatible enum objects)
- Rewrite all 14 app consumers + 4 admin components to Drizzle
- Move the test DB layer to Drizzle + in-process PGlite; convert all 8 integration
  test files + factories (371 tests green)
- Remove Prisma: deps, prisma/ schema+migrations, lib/prisma.ts, Dockerfile prisma
  generate; wire db:generate/migrate/push/studio to drizzle-kit; update Makefile
- Preserve the old seed as scripts/legacy-prisma-seed.cjs (needs a Drizzle rewrite)

app/_admin/site-settings/actions.ts

@@ -1,6 +1,6 @@
 "use server";
 
-import { MediaUsageType } from "@prisma/client";
+import { MediaUsageType } from "@/lib/db/enums";
 import { revalidatePath } from "next/cache";
 import { redirect } from "next/navigation";
 import { isRedirectError } from "next/dist/client/components/redirect-error";
@@ -30,7 +30,10 @@ import { routing } from "@/i18n/routing";
 import { getLocalizedPath } from "@/lib/locale";
 import { removeManagedMediaFile } from "@/lib/media-storage";
 import { mediaFieldInputSchema } from "@/lib/media-validation";
-import { prisma } from "@/lib/prisma";
+import { inArray } from "drizzle-orm";
+
+import { db } from "@/lib/db";
+import { mediaAsset } from "@/lib/db/schema";
 
 async function ensureAdmin() {
   if (!(await isAdminAuthenticated())) {
@@ -60,13 +63,7 @@ function parseJsonObject(rawValue: FormDataEntryValue | null, key: string) {
 
 async function cleanupCreatedMedia(assetIds: string[], uploadedPaths: string[]) {
   if (assetIds.length > 0) {
-    await prisma.mediaAsset.deleteMany({
-      where: {
-        id: {
-          in: Array.from(new Set(assetIds)),
-        },
-      },
-    });
+    await db.delete(mediaAsset).where(inArray(mediaAsset.id, Array.from(new Set(assetIds))));
   }
 
   for (const filePath of Array.from(new Set(uploadedPaths.filter(Boolean)))) {