Adds test_contention_capacity_check_correct_across_multi_round_dispatch_confirm_gap:
a worker at exact capacity (jobs A=8.0 + C=2.0 against 10.0 capacity), with
each job's RUN-state confirmation landing several rounds after its DISPATCH
decision (round 1 dispatch, round 4/5 confirmation, deliberately different
gaps). Drives the real sched_check_host_satisfy() admission check at three
checkpoints, proving Requirement 1 (1.1-1.4) at the outcome level -- a
capacity check, not just a resInUse display value -- per
scheduler-driver-equivalence.md's explicit contention-fixture discipline.
Round 1 review caught three new xce_sched_sim_driver_t fixtures declared
stack-local, amplifying an already-documented (bug-1598, bug-1632)
stack-use-after-return class from the never-joined picker thread
sched_sim_driver_run() spawns. Fixed by declaring them static (safe: each
is written by exactly one call site, and sched_sim_driver_start() memsets
the struct first) -- independently confirmed via 3 full-suite runs with
zero ASAN hits.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AgYRU3zDTqNGV5Jk8aiKLg