-- AlterTable: add username column (nullable, unique)
ALTER TABLE "users" ADD COLUMN "username" TEXT;

-- AlterTable: make nomor_telepon optional
ALTER TABLE "users" ALTER COLUMN "nomor_telepon" DROP NOT NULL;

-- AlterTable: add must_change_password column with default false
ALTER TABLE "users" ADD COLUMN "must_change_password" BOOLEAN NOT NULL DEFAULT false;

-- CreateIndex
CREATE UNIQUE INDEX "users_username_key" ON "users"("username");