feat(parser): implement stripTitle for known prefixes

Two-pass title stripping with loop for stacked titles:
- Dot-prefixes (Dr., Prof.) matched without trailing space
- Word-prefixes (Tante, Frau, Schwester, etc.) matched at
  word boundary
- Stacked titles like "Prof. Dr. Muller" handled correctly
- Single token after title strip goes to lastName (not firstName)

Add 5 "von" last names to KNOWN_LAST_NAMES for correct splitting
of entries like "Freifrau von Massenbach".

15 new test cases + updated 3 existing tests for title behavior.

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

backend/src/test/java/org/raddatz/familienarchiv/service/PersonNameParserTest.java

@@ -190,14 +190,16 @@ class PersonNameParserTest {
     @Test
     void split_dotCompressed_titleFirstNameLastName() {
         PersonNameParser.SplitName result = PersonNameParser.split("Dr.Fr.Zarncke");
-        assertThat(result.firstName()).isEqualTo("Dr. Fr.");
+        assertThat(result.title()).isEqualTo("Dr.");
+        assertThat(result.firstName()).isEqualTo("Fr.");
         assertThat(result.lastName()).isEqualTo("Zarncke");
     }
 
     @Test
     void split_dotCompressed_titleAndLastName() {
         PersonNameParser.SplitName result = PersonNameParser.split("Dr.Zarnke");
-        assertThat(result.firstName()).isEqualTo("Dr.");
+        assertThat(result.title()).isEqualTo("Dr.");
+        assertThat(result.firstName()).isNull();
         assertThat(result.lastName()).isEqualTo("Zarnke");
     }
 
@@ -210,7 +212,8 @@ class PersonNameParserTest {
     @Test
     void split_alreadySpacedDotName_noDoubleSpacing() {
         PersonNameParser.SplitName result = PersonNameParser.split("Dr. Fr. Zarncke");
-        assertThat(result.firstName()).isEqualTo("Dr. Fr.");
+        assertThat(result.title()).isEqualTo("Dr.");
+        assertThat(result.firstName()).isEqualTo("Fr.");
         assertThat(result.lastName()).isEqualTo("Zarncke");
     }
 
@@ -353,12 +356,112 @@ class PersonNameParserTest {
     }
 
     @Test
-    void stripTitle_isPassthrough() {
+    void stripTitle_noPrefix_returnsNull() {
         PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Walter de Gruyter");
         assertThat(result.cleaned()).isEqualTo("Walter de Gruyter");
         assertThat(result.title()).isNull();
     }
 
+    @Test
+    void stripTitle_tante() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Tante Molly");
+        assertThat(result.cleaned()).isEqualTo("Molly");
+        assertThat(result.title()).isEqualTo("Tante");
+    }
+
+    @Test
+    void stripTitle_schwester() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Schwester Hanni");
+        assertThat(result.cleaned()).isEqualTo("Hanni");
+        assertThat(result.title()).isEqualTo("Schwester");
+    }
+
+    @Test
+    void stripTitle_frau() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Frau Bakker");
+        assertThat(result.cleaned()).isEqualTo("Bakker");
+        assertThat(result.title()).isEqualTo("Frau");
+    }
+
+    @Test
+    void stripTitle_cousine_withFullName() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Cousine Emmy Haniel");
+        assertThat(result.cleaned()).isEqualTo("Emmy Haniel");
+        assertThat(result.title()).isEqualTo("Cousine");
+    }
+
+    @Test
+    void stripTitle_freifrau() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Freifrau von Massenbach");
+        assertThat(result.cleaned()).isEqualTo("von Massenbach");
+        assertThat(result.title()).isEqualTo("Freifrau");
+    }
+
+    @Test
+    void stripTitle_dotPrefix_withSpace() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Dr. Sattelmacher");
+        assertThat(result.cleaned()).isEqualTo("Sattelmacher");
+        assertThat(result.title()).isEqualTo("Dr.");
+    }
+
+    @Test
+    void stripTitle_dotPrefix_noSpace() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Dr.von Gelden");
+        assertThat(result.cleaned()).isEqualTo("von Gelden");
+        assertThat(result.title()).isEqualTo("Dr.");
+    }
+
+    @Test
+    void stripTitle_stacked_profDr() {
+        PersonNameParser.TitleResult result = PersonNameParser.stripTitle("Prof. Dr. Muller");
+        assertThat(result.cleaned()).isEqualTo("Muller");
+        assertThat(result.title()).isEqualTo("Prof. Dr.");
+    }
+
+    // --- split — title extraction end-to-end ---
+
+    @Test
+    void split_tante_setsTitle_firstNameNull() {
+        PersonNameParser.SplitName result = PersonNameParser.split("Tante Molly");
+        assertThat(result.title()).isEqualTo("Tante");
+        assertThat(result.firstName()).isNull();
+        assertThat(result.lastName()).isEqualTo("Molly");
+    }
+
+    @Test
+    void split_dotTitle_afterDotNorm() {
+        PersonNameParser.SplitName result = PersonNameParser.split("Dr.Fr.Zarncke");
+        assertThat(result.title()).isEqualTo("Dr.");
+        assertThat(result.firstName()).isEqualTo("Fr.");
+        assertThat(result.lastName()).isEqualTo("Zarncke");
+    }
+
+    @Test
+    void split_dotTitle_noSpace_vonLastName() {
+        PersonNameParser.SplitName result = PersonNameParser.split("Dr.von Gelden");
+        assertThat(result.title()).isEqualTo("Dr.");
+        assertThat(result.firstName()).isNull();
+        assertThat(result.lastName()).isEqualTo("von Gelden");
+    }
+
+    // --- regression: non-prefixes not stripped ---
+
+    @Test
+    void split_walter_noTitleStrip() {
+        PersonNameParser.SplitName result = PersonNameParser.split("Walter de Gruyter");
+        assertThat(result.title()).isNull();
+        assertThat(result.firstName()).isEqualTo("Walter");
+        assertThat(result.lastName()).isEqualTo("de Gruyter");
+    }
+
+    @Test
+    void split_conrad_vonGeldern_noTitleStrip() {
+        PersonNameParser.SplitName result = PersonNameParser.split("Conrad von Geldern");
+        assertThat(result.title()).isNull();
+        assertThat(result.firstName()).isEqualTo("Conrad");
+        assertThat(result.lastName()).isEqualTo("von Geldern");
+    }
+
     // --- stripMaidenName — maiden name extraction ---
 
     @Test