The per-message fork child's Redis/cache/session isolation (#1445) was inline
in forkWithSocketPair() with no test — verified only by watching prod. Extract
it into Handler::resetInheritedConnectionsInChild() (behavior-preserving) and
add ForkChildConnectionResetTest: asserts it disconnects every host-bearing
connection, skips the client/options pseudo-entries, and never throws when the
redis manager is unresolvable. A future refactor that drops a connection now
fails CI instead of re-opening the predis desync flood.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Fabian @ Blax Software
ca90561c9d