renderUsageReports (command-controller) carried the #3268 dedup contract
with no regression test; the PR's added CLI test asserts the opposite
(per-limit CLI rendering shows the note twice). Export renderUsageReports
and add a real regression through it: two accounts sharing one window group
render a provider-wide UsageReport.note once and an identical per-limit note
once. Verified failing on the pre-fix flatMap form (0 and 2 occurrences) and
passing on head (1 and 1).