feat(parser): support // as multi-person separator in parseReceivers

Pre-splits input on "//" before existing logic so each segment is
processed independently through the full pipeline (und/u splitting,
last-name distribution, etc.).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/main/java/org/raddatz/familienarchiv/service/PersonNameParser.java

@@ -1,6 +1,7 @@
 package org.raddatz.familienarchiv.service;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -20,6 +21,7 @@ public class PersonNameParser {
     private static final Pattern GEB_PATTERN = Pattern.compile("\\s+geb\\.\\s+\\S+");
     private static final Pattern PAREN_LAST_NAME = Pattern.compile("\\(([^)]+)\\)\\s*$");
     private static final Pattern MULTI_SEPARATOR = Pattern.compile("\\s+(?:und|u)\\s+");
+    private static final Pattern SLASH_SEPARATOR = Pattern.compile("//");
 
     public record SplitName(String firstName, String lastName) {}
 
@@ -38,6 +40,16 @@ public class PersonNameParser {
     public static List<String> parseReceivers(String raw) {
         if (raw == null || raw.isBlank()) return List.of();
 
+        // 0. Pre-split on "//" — each segment is an independent name entry
+        String[] slashParts = SLASH_SEPARATOR.split(raw, -1);
+        if (slashParts.length > 1) {
+            return Arrays.stream(slashParts)
+                    .map(String::trim)
+                    .filter(s -> !s.isBlank())
+                    .flatMap(segment -> parseReceivers(segment).stream())
+                    .toList();
+        }
+
         // 1. Strip "geb. Xxx" maiden-name annotations
         String cleaned = GEB_PATTERN.matcher(raw).replaceAll("").trim();