m16. shared_metrics.set(enabled=false) purged the renderer's onboarding latch
but left telemetry/shared_metrics/desktop_onboarding/<step>.<event> in the
profile, so a content-free per-profile record outlived the opt-out and the two
sides disagreed on re-opt-in. The Desktop's consent RPC now removes that
directory when it turns collection off (shared_metrics_desktop.
purge_onboarding_latches). Opting out from the CLI (config set / setup wizard)
leaves them until the Desktop's switch is next turned off — see NOT_COVERED.
Test: test_turning_collection_off_drops_the_onboarding_latches — RED on base
(latch file survives), green now.
Probe (review/desktop/probe_optout_set.py):
before: surviving desktop latches: [.../desktop_onboarding, .../intro.reached, ...]
after: surviving desktop latches: [] (only metrics.sqlite3 / outbox remain)
4bb58d3d60