Replace order matching with risk/matching/fulfillment/settlement pipeline

Move XML loading infrastructure and models under service/catalog, and
split order execution into a real pipeline: RiskEngine checks the order,
MatchingEngine matches it, FulfillmentContext books the resulting trades,
and SettlementContext resolves winning markets. GuessMarketContext.buyShares
becomes placeOrder(price, quantity), and TradingMechanism.buy now returns
matched trades directly instead of a single TradeExecution.

5 files changed, 8 insertions, 10 deletions

diff --git a/api/src/main/java/market/guess/api/CatalogContext.java b/api/src/main/java/market/guess/api/CatalogContext.java
index c980ba8..413a81c 100644
--- a/api/src/main/java/market/guess/api/CatalogContext.java
+++ b/api/src/main/java/market/guess/api/CatalogContext.java
@@ -6,7 +6,7 @@ import market.guess.model.event.EventDetailDTO;
 import market.guess.model.event.EventSummaryDTO;
 
 public interface CatalogContext {
-  Result<LoadResultDTO> loadEvents(Path path);
+  Result<LoadResult> loadEvents(Path path);
 
   Result<List<EventSummaryDTO>> getAllEvents();
 
@@ -14,5 +14,5 @@ public interface CatalogContext {
 
   Result<Void> saveState(Path path);
 
-  Result<LoadResultDTO> restoreState(Path path);
+  Result<LoadResult> restoreState(Path path);
 }
diff --git a/api/src/main/java/market/guess/api/GuessMarketContext.java b/api/src/main/java/market/guess/api/GuessMarketContext.java
index 7ec7323..e11defb 100644
--- a/api/src/main/java/market/guess/api/GuessMarketContext.java
+++ b/api/src/main/java/market/guess/api/GuessMarketContext.java
@@ -1,10 +1,11 @@
 package market.guess.api;
 
+import java.math.BigDecimal;
 import market.guess.model.event.EventDetailDTO;
 
 public interface GuessMarketContext {
-  Result<PurchaseReceiptDTO> buyShares(
-      String userName, String eventKey, String optionKey, int quantity);
+  Result<PurchaseReceiptDTO> placeOrder(
+      String userName, String eventKey, String optionKey, BigDecimal price, long quantity);
 
   Result<EventDetailDTO> settleEvent(String userName, String eventKey, String winningOptionKey);
 }
diff --git a/api/src/main/java/market/guess/api/LoadResult.java b/api/src/main/java/market/guess/api/LoadResult.java
new file mode 100644
index 0000000..6ffe68d
--- /dev/null
+++ b/api/src/main/java/market/guess/api/LoadResult.java
@@ -0,0 +1,3 @@
+package market.guess.api;
+
+public record LoadResult(String source, int eventsLoaded) {}
diff --git a/api/src/main/java/market/guess/api/LoadResultDTO.java b/api/src/main/java/market/guess/api/LoadResultDTO.java
deleted file mode 100644
index 95c23e7..0000000
--- a/api/src/main/java/market/guess/api/LoadResultDTO.java
+++ /dev/null
@@ -1,3 +0,0 @@
-package market.guess.api;
-
-public record LoadResultDTO(String source, int eventsLoaded) {}
diff --git a/api/src/main/java/market/guess/api/ProblemDTO.java b/api/src/main/java/market/guess/api/ProblemDTO.java
deleted file mode 100644
index 682372b..0000000
--- a/api/src/main/java/market/guess/api/ProblemDTO.java
+++ /dev/null
@@ -1,3 +0,0 @@
-package market.guess.api;
-
-public record ProblemDTO(String code, String humanizedMessage, String location) {}