The Full Suite (non-blocking) workflow has been red for 30+ runs on main.
Diagnosis: the @fusion/engine [1/2], [2/2] and @fusion/core [2/2] shard
slices were SIGKILLed at their watchdog budgets (405s/405s/338s), not because
they hang but because those budgets are too tight for current wall-clock.
Local baselines (this machine, all pass, exit 0):
- engine [2/2]: 145s wall / 309 files
- core [2/2]: 283s wall / 172 files (old budget was only 338s!)
deriveBudgetMs tightens the budget to expected*3.5 whenever the committed
scripts/test-timings.json is <30d old. The snapshot (2026-06-03) undercounts
the import- and real-git-subprocess overhead of these heavy slices, so the
'fresh' snapshot produced a too-tight, false-kill budget on slower CI runners
-- the exact failure mode the floor/ceiling band exists to prevent.
Fix (plan KTD-2): raise the shard band floor 5min -> 15min so the heaviest
slices can't be tightened into a false-kill, while a true hang is still bounded
far under the job's 60min ceiling. Mirrors the dashboard-lane heavy-lane floor.
Follow-up: refresh scripts/test-timings.json from a default-branch CI run.
74e056ed99