Run the leader with: Terminal 1 (leader): IS_LEADER=true BROKER_ID=broker-0 BROKER_PORT=5001 go run ./cmd/broker

Run the follower with: Terminal 2 (follower): IS_LEADER=false BROKER_ID=broker-1 BROKER_PORT=5002 LEADER_ADDR=localhost:5001 go run ./cmd/broker

1. Append to the leader: curl -X POST localhost:5001/append -H "Content-Type: application/json" -d '{"sound":"rain","key":"outdoor"}'

2. Wait a second, then read from the follower: curl "localhost:5002/read?offset=0"