CLUSTER commands are not supported on Upstash: disable cluster mode in your client

# CLUSTER commands are not supported on Upstash Redis

## What you see

Errors mentioning cluster, slots, or MOVED/ASK redirections when your
client tries cluster discovery, or 400s on CLUSTER subcommands over
REST.

## Why

Upstash manages sharding and replication internally. There is no
client-visible cluster topology to discover.

## Fix

- Disable cluster mode in your client. In ioredis, use a standalone
  Redis instance, not Cluster. In redis-py, use Redis, not RedisCluster.
- Remove any cluster slots configuration or startup-node lists.
  Point the client at the single Upstash endpoint.
- If you chose Upstash for multi-region reads, that is the Global
database feature, not Redis Cluster. Configure regions in the console
  instead.

## Verify

INFO replication (over RESP) or a plain PING/SET/GET cycle succeeds
with the client in standalone mode.