Surface unrealized (latent) gain on the existing balance surfaces, no new
visualization (decision 2026-06-04).
Service:
- AccountLatestSnapshot gains account `kind` + `latest_snapshot_line_id`, so
the table knows which rows are detailed and where their holdings live.
- getAccountLatentGainByLine(lineId) folds a line's holdings through the
existing computeUnrealizedGain (shares the book_cost=0 / NULL -> N/A guard).
- rollupLatentGain(accounts): pure aggregation by asset class, by envelope
(vehicle_type, 'none' bucket), and grand total; per-bucket % denominator is
the known book_cost only (null when none), mirroring the aggregate guard.
Hook (useBalanceOverview):
- Prefetches per-detailed-account latent gain in parallel (failures isolated),
exposes latentGainByAccount + latentGainRollup. Simple accounts skipped.
UI:
- BalanceAccountsTable: expandable detailed rows -> per-security value + latent
gain %; a latent-gain column (shown only when a detailed account has one);
a summary block aggregating latent gain by asset class / envelope.
- BalanceOverviewCard: total latent gain line (hidden without detailed accounts).
- N/A rendered (never divide-by-zero) when book_cost is NULL or 0; partial-%
flag when some positions lack a cost basis.
Native non-CAD currency display de-scoped this round (untestable while all
securities are CAD). Modified Dietz return columns (#204) unchanged.
i18n: balance.latentGain.* in FR + EN. Focused unit tests for
getAccountLatentGainByLine and rollupLatentGain (grouping, 'none' envelope,
null-% / unknown book_cost, empty).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
