feat(document): remove conversation service methods

Delete getConversationFiltered (the endpoint's only caller is gone) and
the dead 2-arg getConversation(personA, personB) which had zero callers,
along with both getConversationFiltered test blocks. The hasSender/
hasReceiver specifications stay — document search still uses them.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/main/java/org/raddatz/familienarchiv/document/DocumentService.java

@@ -918,22 +918,6 @@ public class DocumentService {
                 .orElse("");
     }
 
-    // 2. SPEZIALITÄT: Der Schriftwechsel
-    // Findet alle Briefe ZWISCHEN zwei Personen (egal wer Sender/Empfänger war)
-    public List<Document> getConversation(UUID personA, UUID personB) {
-
-        // Fall 1: A schreibt an B
-        Specification<Document> aToB = Specification.where(hasSender(personA)).and(hasReceiver(personB));
-
-        // Fall 2: B schreibt an A
-        Specification<Document> bToA = Specification.where(hasSender(personB)).and(hasReceiver(personA));
-
-        // Wir wollen (A->B) ODER (B->A)
-        Specification<Document> conversation = aToB.or(bToA);
-
-        return documentRepository.findAll(conversation, Sort.by(Sort.Direction.ASC, "documentDate"));
-    }
-
     @Transactional
     public void updateScriptType(UUID documentId, ScriptType scriptType) {
         Document doc = getDocumentById(documentId);
@@ -992,15 +976,6 @@ public class DocumentService {
         return documentRepository.findByReceiversId(receiverId);
     }
 
-    public List<Document> getConversationFiltered(UUID senderId, UUID receiverId, LocalDate from, LocalDate to, Sort sort) {
-        LocalDate dateFrom = (from != null) ? from : LocalDate.parse("0000-01-01");
-        LocalDate dateTo = (to != null) ? to : LocalDate.now();
-        if (receiverId == null) {
-            return documentRepository.findSinglePersonCorrespondence(senderId, dateFrom, dateTo, sort);
-        }
-        return documentRepository.findConversation(senderId, receiverId, dateFrom, dateTo, sort);
-    }
-
     public long getIncompleteCount() {
         return documentRepository.countByMetadataCompleteFalse();
     }

backend/src/test/java/org/raddatz/familienarchiv/document/DocumentServiceTest.java

@@ -1128,53 +1128,6 @@ class DocumentServiceTest {
                 .isEqualTo("19650332_Mueller_Hans");
     }
 
-    // ─── getConversationFiltered ───────────────────────────────────────────────
-
-    @Test
-    void getConversationFiltered_passesGivenDates_whenFromAndToAreProvided() {
-        UUID senderId = UUID.randomUUID();
-        UUID receiverId = UUID.randomUUID();
-        LocalDate from = LocalDate.of(1940, 1, 1);
-        LocalDate to = LocalDate.of(1960, 12, 31);
-        Sort sort = Sort.by(Sort.Direction.ASC, "documentDate");
-        when(documentRepository.findConversation(senderId, receiverId, from, to, sort))
-                .thenReturn(List.of());
-
-        documentService.getConversationFiltered(senderId, receiverId, from, to, sort);
-
-        verify(documentRepository).findConversation(senderId, receiverId, from, to, sort);
-    }
-
-    @Test
-    void getConversationFiltered_usesMinDateForFrom_whenFromIsNull() {
-        UUID senderId = UUID.randomUUID();
-        UUID receiverId = UUID.randomUUID();
-        Sort sort = Sort.by(Sort.Direction.ASC, "documentDate");
-        when(documentRepository.findConversation(eq(senderId), eq(receiverId), any(LocalDate.class), any(LocalDate.class), eq(sort)))
-                .thenReturn(List.of());
-
-        documentService.getConversationFiltered(senderId, receiverId, null, null, sort);
-
-        ArgumentCaptor<LocalDate> fromCaptor = ArgumentCaptor.forClass(LocalDate.class);
-        verify(documentRepository).findConversation(eq(senderId), eq(receiverId), fromCaptor.capture(), any(LocalDate.class), eq(sort));
-        assertThat(fromCaptor.getValue()).isEqualTo(LocalDate.parse("0000-01-01"));
-    }
-
-    @Test
-    void getConversationFiltered_usesTodayForTo_whenToIsNull() {
-        UUID senderId = UUID.randomUUID();
-        UUID receiverId = UUID.randomUUID();
-        Sort sort = Sort.by(Sort.Direction.ASC, "documentDate");
-        when(documentRepository.findConversation(eq(senderId), eq(receiverId), any(LocalDate.class), any(LocalDate.class), eq(sort)))
-                .thenReturn(List.of());
-
-        documentService.getConversationFiltered(senderId, receiverId, null, null, sort);
-
-        ArgumentCaptor<LocalDate> toCaptor = ArgumentCaptor.forClass(LocalDate.class);
-        verify(documentRepository).findConversation(eq(senderId), eq(receiverId), any(LocalDate.class), toCaptor.capture(), eq(sort));
-        assertThat(toCaptor.getValue()).isEqualTo(LocalDate.now());
-    }
-
     // ─── updateDocumentTags — empty tag in list ───────────────────────────────
 
     @Test
@@ -1760,35 +1713,6 @@ class DocumentServiceTest {
                 .isEqualTo(Sort.by(Sort.Direction.DESC, "updatedAt"));
     }
 
-    // ─── getConversationFiltered (single-person mode) ─────────────────────────
-
-    @Test
-    void getConversationFiltered_callsSinglePersonQuery_whenReceiverIdIsNull() {
-        UUID personId = UUID.randomUUID();
-        Sort sort = Sort.by(Sort.Direction.DESC, "documentDate");
-        when(documentRepository.findSinglePersonCorrespondence(eq(personId), any(), any(), eq(sort)))
-                .thenReturn(List.of());
-
-        documentService.getConversationFiltered(personId, null, null, null, sort);
-
-        verify(documentRepository).findSinglePersonCorrespondence(eq(personId), any(), any(), eq(sort));
-        verify(documentRepository, never()).findConversation(any(), any(), any(), any(), any());
-    }
-
-    @Test
-    void getConversationFiltered_callsBilateralQuery_whenReceiverIdIsSet() {
-        UUID senderId = UUID.randomUUID();
-        UUID receiverId = UUID.randomUUID();
-        Sort sort = Sort.by(Sort.Direction.DESC, "documentDate");
-        when(documentRepository.findConversation(eq(senderId), eq(receiverId), any(), any(), eq(sort)))
-                .thenReturn(List.of());
-
-        documentService.getConversationFiltered(senderId, receiverId, null, null, sort);
-
-        verify(documentRepository).findConversation(eq(senderId), eq(receiverId), any(), any(), eq(sort));
-        verify(documentRepository, never()).findSinglePersonCorrespondence(any(), any(), any(), any());
-    }
-
     // ─── searchDocuments — SENDER sort includes documents with null sender ─────
 
     @Test