Switch auth to plain-text password env var (remove bcrypt)

- Replace ADMIN_PASSWORD_HASH with ADMIN_PASSWORD in auth route and docker-compose
- Remove bcryptjs / @types/bcryptjs dependencies
- Delete scripts/hashPassword.ts (no longer needed)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -11,7 +11,7 @@ services:
       - PORT=3001
       - DATABASE_URL=file:./data/rackmapper.db
       - ADMIN_USERNAME=${ADMIN_USERNAME:-admin}
-      - ADMIN_PASSWORD_HASH=${ADMIN_PASSWORD_HASH}
+      - ADMIN_PASSWORD=${ADMIN_PASSWORD}
       - JWT_SECRET=${JWT_SECRET}
       - JWT_EXPIRY=${JWT_EXPIRY:-8h}
     volumes: