Follow-up to #6957, from the review:
1. avg-per-PDF no longer blends unsynced units over synced-only docs. It now
divides SYNCED units (spendUnitsThisPeriod) by synced docs, so numerator and
denominator cover the same population; combined-billing pendingUnits (units-
only, no doc count) no longer inflates the average. The "meter units" figure
still shows synced+pending (total current usage).
2. Empty-state: docs==0 with pending meter units (combined-billing, unsynced-
only) now shows a "{n} meter units pending sync from linked instances" note
instead of a bare "0 PDFs" headline with a count-less summary and no split.
New i18n key + a UnsyncedOnly story variant.
3. uniquePdfsThisPeriod wording softened to be accurate: the fingerprint is over
a charge's whole input SET, so the same file reused across different groupings
(standalone vs a later merge) counts per grouping — a close approximation,
exact for the single-input common case. Updated the FE type doc + the
WalletLedgerEntry.document_fingerprint javadoc.
Connor Yoh
4648cb8b41