Merge branch 'netem-bug-fixes'

Stephen Hemminger says:

====================
netem: bug fixes

These bugs were found when doing AI-assisted review of sch_netem.c
during investigation of the packet duplication recursion problem
addressed in Jamal's series.

The fixes cover:

 - probability gaps in the 4-state Markov loss model
 - queue limit not accounting for reordered packets
 - PRNG reseeded on every tc change, breaking reproducibility
 - slot configuration not validated (inverted ranges, negative
   delays, negative limits)
 - slot delay arithmetic overflow for ranges above ~2.1 seconds
 - negative latency and jitter wrapping to huge time_to_send
   values via u64 arithmetic
====================

Link: https://patch.msgid.link/20260418032027.900913-1-stephen@networkplumber.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>