workout_reliability_test is order-dependent: fails in the full suite, passes in isolation #259

test/workout_reliability_test.dart — "DeriveScheduler — live-workout gate a
queued job stays parked for the session, then runs on release" fails
intermittently in the full suite (Expected: <1> Actual: <0>) and passes
every time in isolation:

flutter test test/workout_reliability_test.dart --concurrency=1   # green
flutter test --concurrency=1                                      # sometimes red on this one test

I verified the same failure on a pristine main checkout in a clean worktree,
so it's not related to any local changes — it looks like order-dependent
static state that an earlier test in the full run leaves behind (the suite
runs with --concurrency=1, so it's ordering, not parallelism). Across many
full runs today it failed maybe one run in three.

Flagging it mainly so PR authors don't chase it as their own regression when
CI trips on it — and so whoever knows the DeriveScheduler internals can spot
which earlier test leaks into it. Happy to help bisect the test order if
useful.