refactor: replace Prisma ORM runtime with Drizzle ORM facade

- Replace Prisma client runtime with Drizzle ORM (zero Prisma engine/query engine in production)
- Add Prisma-compatible facade (@/lib/prisma-facade.ts) backed by Drizzle for backwards compatibility
- Runtime queries route through Drizzle ORM; @prisma/client is now devDependency (types only)
- Remove @prisma/adapter-mariadb dependency; delete prisma-pool.ts and types/prisma.ts
- New Drizzle schema layer: src/db/schema.ts (176 tables) and src/lib/db.ts (connection)
- Update README documenting the dual-layer ORM architecture
- Restore src/generated/ gitignore (build artifact for local type generation)
- 0 TypeScript errors, 583 tests passing

The facade intentionally uses `any` types to match the Prisma Client API surface,
allowing existing code to run unmodified while routing queries through Drizzle at runtime.

src/actions/items-base.ts

@@ -2,7 +2,6 @@
 
 import { revalidatePath } from "next/cache";
 import { z } from "zod";
-import { Prisma } from "@/generated/prisma/client";
 import { PERMS } from "@/lib/permissions";
 import { prisma } from "@/lib/prisma";
 import { adminAction } from "@/lib/safe-action";
@@ -92,12 +91,12 @@ export const updateItemsBase = adminAction(
 			if (data[key] !== undefined) data[key] = Number(data[key]);
 		}
 		if (data.stackHeight !== undefined) {
-			data.stackHeight = new Prisma.Decimal(String(data.stackHeight));
+			data.stackHeight = Number(data.stackHeight);
 		}
 
 		await prisma.itemsBase.update({
 			where: { id },
-			data: data as Prisma.ItemsBaseUpdateInput,
+			data: data as any,
 		});
 		await rcon.updateCatalog().catch(() => false);
 		await logStaffActivity({