feat(admin-auth): support username login and add dashboard logout

packages/db/prisma/migrations/20260210173127_username_auth/migration.sql

@@ -0,0 +1,11 @@
+/*
+  Warnings:
+
+  - A unique constraint covering the columns `[username]` on the table `user` will be added. If there are existing duplicate values, this will fail.
+
+*/
+-- AlterTable
+ALTER TABLE "user" ADD COLUMN     "username" TEXT;
+
+-- CreateIndex
+CREATE UNIQUE INDEX "user_username_key" ON "user"("username");

packages/db/prisma/schema.prisma

@@ -22,6 +22,7 @@ model User {
   id            String    @id
   name          String
   email         String
+  username      String?   @unique
   emailVerified Boolean   @default(false)
   image         String?
   createdAt     DateTime  @default(now())