platformio test discovers and runs whatever test_* directories exist, so
it never notices when test/native-suite-count drifts from the actual
directory count. That reconciliation lived only in bin/run-tests.sh, which
CI does not invoke - so a stale or unbumped count sailed through PRs
(develop itself shipped 38 dirs against a 37 file).
Add a standalone suite-count-check job to test_native.yml that mirrors
run-tests.sh's exact counting logic and fails on a mismatch. It runs on
every PR via main_matrix's test-native job, with no build step so it fails
fast. Bump native-suite-count to 38 to match the current suites.
clod helped too
nomdetom
efd620b552