implemented transaction propagation via event bus

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

core/src/main/java/de/srsoftware/umbrella/core/ModuleRegistry.java

@@ -53,6 +53,10 @@ public class ModuleRegistry {
 		}
 	}
 
+	public static AccountingService accountingService() {
+		return singleton.accountingService;
+	}
+
 	public static BookmarkService bookmarkService(){
 		return singleton.bookmarkService;
 	}

core/src/main/java/de/srsoftware/umbrella/core/api/AccountingService.java

@@ -1,5 +1,33 @@
 /* © SRSoftware 2025 */
 package de.srsoftware.umbrella.core.api;
 
+import de.srsoftware.tools.Mappable;
+import de.srsoftware.umbrella.core.constants.Field;
+import de.srsoftware.umbrella.core.model.Account;
+import de.srsoftware.umbrella.core.model.Transaction;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static de.srsoftware.umbrella.core.Util.mapValues;
+
 public interface AccountingService {
+	public record AccountData(Account account, List<Transaction> transactions, HashMap<Long, UmbrellaUser> userMap) implements Mappable {
+		public static AccountData of(Account account, List<Transaction> transactions, HashMap<Long, UmbrellaUser> userMap) {
+			return new AccountData(account, transactions, userMap);
+		}
+
+		@Override
+		public Map<String, Object> toMap() {
+			return Map.of(
+				Field.ACCOUNT,account.toMap(),
+				Field.TRANSACTIONS,transactions.stream().map(Transaction::toMap).toList(),
+				Field.USER_LIST,mapValues(userMap)
+			);
+		}
+	}
+
+	AccountData loadAccount(long accountId);
 }