Extracts 3 wall-clock-sensitive assertions (combo-quota-share cooldown
ceiling x2, circuit-breaker HALF_OPEN race) into tests/unit/serial/
(--test-concurrency=1, the repo's established remedy for this class of
test) and widens their margins, since a starved CI-runner event loop can
blow even a serialized test's timing window. Also adds an explicit 30s
vitest timeout to the MCP audit shutdown test, which had no override and
inherited vitest's 5000ms default.
Regression proof: reproduced RED locally under real devbox CPU
contention (2644ms/1796ms elapsed vs the old 1500ms ceiling, exactly the
reported failure mode); confirmed GREEN after the fix under the same
contention.
* test(ci): quarantine concurrency-sensitive flakes into a serial pass (tests/unit/serial/)
glm-coding-plan-monthly-3580, quota-division-blocks and provider-health-autopilot
fail under --test-concurrency>1 CPU contention but pass isolated (v3.8.45 release
benchmark: this class cost ~28min re-runs per CI round). They now live in
tests/unit/serial/ and run in a dedicated --test-concurrency=1 step appended to
every runner (test:unit, :ci, :ci:shard, :fast, :shard:1/2, coverage:runner —
sharded variants shard the serial pass too, so concurrent shard jobs never
self-collide). Discovery + TIA gates know the new glob; stryker.conf.json path
updated. Guard: tests/unit/test-serial-quarantine.test.ts (4 tests).
* test(ci): quarantine combo-health-autopilot too (async logger writes after test end under load)
Fresh evidence from this PR's own CI: all 3 subtests pass but an async log write
lands after the test ends (ENOENT app.log -> uncaughtException) — same
concurrency-flake family. Moved to tests/unit/serial/, imports adjusted,
stryker path updated, guard test now asserts 4 quarantined files.
