Wire event ledger movements, show winning market by name, seed LMSR subsidy

- Event ledger now grows on purchase and shrinks on payout, mirroring
  the exact amounts moved on the buyer's ledger (it previously had a
  Ledger object that nothing ever wrote to).
- Settlement and event-detail views now show the winning market's
  display name instead of its raw key; event details are viewable for
  settled events too (the picker previously excluded anything not
  ACTIVE).
- LMSR events seed their ledger with a SUBSIDY entry for the market
  maker's worst-case loss (b * ln(outcomes)), reusing the existing
  cost() function rather than recomputing the formula.

1 files changed, 1 insertions, 1 deletions

diff --git a/api/src/main/java/market/guess/model/event/EventDetailDTO.java b/api/src/main/java/market/guess/model/event/EventDetailDTO.java
index e45458b..9f59b53 100644
--- a/api/src/main/java/market/guess/model/event/EventDetailDTO.java
+++ b/api/src/main/java/market/guess/model/event/EventDetailDTO.java
@@ -8,4 +8,4 @@ public record EventDetailDTO(
     EventSummaryDTO summary,
     MarketStateDTO state,
     List<TradeRowDTO> history,
-    String winningOption) {}
+    String settledMarket) {}