feat: add mii gender property to database

will have to create a migration script

prisma/migrations/20250505164523_mii_gender/migration.sql

@@ -0,0 +1,5 @@
+-- CreateEnum
+CREATE TYPE "MiiGender" AS ENUM ('MALE', 'FEMALE');
+
+-- AlterTable
+ALTER TABLE "miis" ADD COLUMN     "gender" "MiiGender";

prisma/schema.prisma

@@ -72,6 +72,7 @@ model Mii {
 
   firstName      String
   lastName       String
+  gender         MiiGender?
   islandName     String
   allowedCopying Boolean
 
@@ -111,6 +112,11 @@ model Report {
   @@map("reports")
 }
 
+enum MiiGender {
+  MALE
+  FEMALE
+}
+
 enum ReportType {
   MII
   USER