Introduces REDIS_SOCKET_KEEPALIVE and wires socket_keepalive=True
through to every Redis client created by get_redis_connection
(plain, cluster and sentinel paths, sync and async). When enabled,
the kernel sends TCP keepalive probes on idle connections so
half-closed sockets (e.g. after a silent firewall/LB reset or a NIC
flap) are detected before the next command lands on them and the
request never sees a "Connection reset by peer" error.
Defaults to off so existing deployments see no behavioural change.
Operators who want the protection set REDIS_SOCKET_KEEPALIVE=true
in their environment.
Co-authored-by: Claude <noreply@anthropic.com>
