Surface the §16-traceability evidence behind the supply forecast that
previously lived only in exports: future_market.future_supply (§9.3
supply-pressure breakdown — open/hidden stock, absorption, months of
pressure, future units, pressure index) and future_market.future_competitors
(§9.7 relevance-weighted pipeline, sorted by relevance desc). New
ForecastFutureSupplyBlock as subsection 6.6 (+ section-6-6 nav),
complementing 6.1's per-horizon aggregates.
- Fix FutureSupply/FutureSupplyBreakdown/FutureCompetitor optionality in
forecast.ts to match the backend (FutureSupplyPressure/Competitor): null
metrics typed + rendered «нет данных», never a fabricated 0.
- Supply panel gates on computed metrics (index/pressure), NOT open/hidden
unit stocks — so the empty-supply_layers state (pre Monday-worker, every
parcel today) hides the panel instead of falsely showing "0 ед."; the
competitor table still renders. hasSupplySignal shared in forecast-helpers.
- RU labels reuse report_pdf/excel export wording. Graceful on partial/202.
Part of #958; surfaces #950 future-supply data.
