refactor(training-export): route export services through owning services

SegmentationTrainingExportService and TrainingDataExportService each injected
TranscriptionBlockRepository, AnnotationRepository and DocumentRepository
directly. They now go through:

- TranscriptionBlockQueryService (extended) for the three eligible-block
  queries — used over TranscriptionService to keep
  SenderModelService → TrainingDataExportService → TranscriptionService cycle-free.
- AnnotationService.findById (new) — read API on the annotation domain.
- DocumentService.findById (already added in #417 commit 3).

The TrainingDataExportServiceTest @DataJpaTest delegates the new service reads
to the real JPA repositories via Mockito stubs in the new makeService helper,
so the integration coverage stays unchanged.

Refs #417 (C6.2 violations #6 and #7).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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

@@ -17,6 +17,7 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.UUID;
 
 @Slf4j
@@ -32,6 +33,10 @@ public class AnnotationService {
         return annotationRepository.findByDocumentId(documentId);
     }
 
+    public Optional<DocumentAnnotation> findById(UUID id) {
+        return annotationRepository.findById(id);
+    }
+
     @Transactional
     public DocumentAnnotation createAnnotation(UUID documentId, CreateAnnotationDTO dto, UUID userId, String fileHash) {
         DocumentAnnotation annotation = DocumentAnnotation.builder()

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

@@ -8,9 +8,6 @@ import org.apache.pdfbox.rendering.PDFRenderer;
 import org.raddatz.familienarchiv.model.Document;
 import org.raddatz.familienarchiv.model.DocumentAnnotation;
 import org.raddatz.familienarchiv.model.TranscriptionBlock;
-import org.raddatz.familienarchiv.repository.AnnotationRepository;
-import org.raddatz.familienarchiv.repository.DocumentRepository;
-import org.raddatz.familienarchiv.repository.TranscriptionBlockRepository;
 import org.springframework.stereotype.Service;
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
@@ -27,13 +24,13 @@ import java.util.zip.ZipOutputStream;
 @Slf4j
 public class SegmentationTrainingExportService {
 
-    private final TranscriptionBlockRepository blockRepository;
+    private final TranscriptionBlockQueryService transcriptionBlockQueryService;
-    private final AnnotationRepository annotationRepository;
+    private final AnnotationService annotationService;
-    private final DocumentRepository documentRepository;
+    private final DocumentService documentService;
     private final FileService fileService;
 
     public List<TranscriptionBlock> querySegmentationBlocks() {
-        return blockRepository.findSegmentationBlocks();
+        return transcriptionBlockQueryService.findSegmentationBlocks();
     }
 
     public StreamingResponseBody exportToZip() {
@@ -51,14 +48,14 @@ public class SegmentationTrainingExportService {
         // Pre-fetch annotations keyed by id
         Map<UUID, DocumentAnnotation> annotations = new HashMap<>();
         for (TranscriptionBlock b : blocks) {
-            annotationRepository.findById(b.getAnnotationId())
+            annotationService.findById(b.getAnnotationId())
                     .ifPresent(a -> annotations.put(a.getId(), a));
         }
 
         // Pre-fetch documents keyed by id
         Map<UUID, Document> documents = new HashMap<>();
         for (UUID docId : byDoc.keySet()) {
-            documentRepository.findById(docId).ifPresent(d -> documents.put(d.getId(), d));
+            documentService.findById(docId).ifPresent(d -> documents.put(d.getId(), d));
         }
 
         return out -> {

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

@@ -8,9 +8,6 @@ import org.apache.pdfbox.rendering.PDFRenderer;
 import org.raddatz.familienarchiv.model.Document;
 import org.raddatz.familienarchiv.model.DocumentAnnotation;
 import org.raddatz.familienarchiv.model.TranscriptionBlock;
-import org.raddatz.familienarchiv.repository.AnnotationRepository;
-import org.raddatz.familienarchiv.repository.DocumentRepository;
-import org.raddatz.familienarchiv.repository.TranscriptionBlockRepository;
 import org.springframework.stereotype.Service;
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
@@ -28,13 +25,13 @@ import java.util.zip.ZipOutputStream;
 @Slf4j
 public class TrainingDataExportService {
 
-    private final TranscriptionBlockRepository blockRepository;
+    private final TranscriptionBlockQueryService transcriptionBlockQueryService;
-    private final AnnotationRepository annotationRepository;
+    private final AnnotationService annotationService;
-    private final DocumentRepository documentRepository;
+    private final DocumentService documentService;
     private final FileService fileService;
 
     public List<TranscriptionBlock> queryEligibleBlocks() {
-        return blockRepository.findEligibleKurrentBlocks();
+        return transcriptionBlockQueryService.findEligibleKurrentBlocks();
     }
 
     public StreamingResponseBody exportToZip() {
@@ -42,7 +39,7 @@ public class TrainingDataExportService {
     }
 
     public List<TranscriptionBlock> queryBlocksForSender(UUID personId) {
-        return blockRepository.findManualKurrentBlocksByPerson(personId);
+        return transcriptionBlockQueryService.findManualKurrentBlocksByPerson(personId);
     }
 
     public StreamingResponseBody exportForSender(UUID personId) {
@@ -63,14 +60,14 @@ public class TrainingDataExportService {
         // Pre-fetch annotations keyed by id
         Map<UUID, DocumentAnnotation> annotations = new HashMap<>();
         for (TranscriptionBlock b : blocks) {
-            annotationRepository.findById(b.getAnnotationId())
+            annotationService.findById(b.getAnnotationId())
                     .ifPresent(a -> annotations.put(a.getId(), a));
         }
 
         // Pre-fetch documents keyed by id
         Map<UUID, Document> documents = new HashMap<>();
         for (UUID docId : byDoc.keySet()) {
-            documentRepository.findById(docId).ifPresent(d -> documents.put(d.getId(), d));
+            documentService.findById(docId).ifPresent(d -> documents.put(d.getId(), d));
         }
 
         return out -> {

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

@@ -1,6 +1,7 @@
 package org.raddatz.familienarchiv.service;
 
 import lombok.RequiredArgsConstructor;
+import org.raddatz.familienarchiv.model.TranscriptionBlock;
 import org.raddatz.familienarchiv.repository.CompletionStatsRow;
 import org.raddatz.familienarchiv.repository.TranscriptionBlockRepository;
 import org.springframework.stereotype.Service;
@@ -24,4 +25,16 @@ public class TranscriptionBlockQueryService {
         }
         return result;
     }
+
+    public List<TranscriptionBlock> findSegmentationBlocks() {
+        return blockRepository.findSegmentationBlocks();
+    }
+
+    public List<TranscriptionBlock> findEligibleKurrentBlocks() {
+        return blockRepository.findEligibleKurrentBlocks();
+    }
+
+    public List<TranscriptionBlock> findManualKurrentBlocksByPerson(UUID personId) {
+        return blockRepository.findManualKurrentBlocksByPerson(personId);
+    }
 }

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

@@ -27,6 +27,7 @@ import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.*;
 
@@ -60,7 +61,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(manualBlock(docId, annotId, "Liebe Mutter"));
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         StreamingResponseBody body = service.exportToZip();
         byte[] zipBytes = stream(body);
@@ -79,7 +80,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(block);
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         StreamingResponseBody body = service.exportToZip();
         assertThat(zipEntryNames(stream(body))).isEmpty();
@@ -92,7 +93,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(manualBlock(docId, annotId, "Liebe Tante"));
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         StreamingResponseBody body = service.exportToZip();
         byte[] zipBytes = stream(body);
@@ -110,7 +111,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(block);
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         StreamingResponseBody body = service.exportToZip();
         assertThat(zipEntryNames(stream(body))).isNotEmpty();
@@ -127,7 +128,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(block);
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         StreamingResponseBody body = service.exportToZip();
         assertThat(zipEntryNames(stream(body))).isEmpty();
@@ -143,7 +144,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(manualBlock(docId, annotId, "Zweite Zeile"));
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         byte[] zipBytes = stream(service.exportToZip());
         var names = zipEntryNames(zipBytes);
@@ -160,7 +161,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(manualBlock(docId, annotId, expectedText));
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         byte[] zipBytes = stream(service.exportToZip());
         String xmlContent = readZipEntry(zipBytes, ".xml");
@@ -174,7 +175,7 @@ class TrainingDataExportServiceTest {
         blockRepository.save(manualBlock(docId, annotId, "A & B < C > D"));
 
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         byte[] zipBytes = stream(service.exportToZip());
         String xmlContent = readZipEntry(zipBytes, ".xml");
@@ -196,7 +197,7 @@ class TrainingDataExportServiceTest {
         when(fileService.downloadFileBytes("fail.pdf")).thenThrow(new FileService.StorageFileNotFoundException("missing"));
         when(fileService.downloadFileBytes("ok.pdf")).thenReturn(minimalPdfBytes);
 
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         byte[] zipBytes = stream(service.exportToZip());
         var names = zipEntryNames(zipBytes);
@@ -209,13 +210,34 @@ class TrainingDataExportServiceTest {
     @Test
     void queryEligibleBlocks_returnsEmpty_whenNoEnrolledDocuments() {
         FileService fileService = mockFileService();
-        TrainingDataExportService service = new TrainingDataExportService(blockRepository, annotationRepository, documentRepository, fileService);
+        TrainingDataExportService service = makeService(fileService);
 
         assertThat(service.queryEligibleBlocks()).isEmpty();
     }
 
     // ─── helpers ─────────────────────────────────────────────────────────────
 
+    /**
+     * Builds the export service with mocked owning services that transparently
+     * delegate every read to the real JPA repositories provided by {@code @DataJpaTest}.
+     * Keeps the integration test green after #417's layering refactor without
+     * pulling the full transcription/annotation/document service trees into scope.
+     */
+    private TrainingDataExportService makeService(FileService fileService) {
+        TranscriptionBlockQueryService blockQueryService = mock(TranscriptionBlockQueryService.class);
+        AnnotationService annotationService = mock(AnnotationService.class);
+        DocumentService documentService = mock(DocumentService.class);
+        when(blockQueryService.findEligibleKurrentBlocks())
+                .thenAnswer(inv -> blockRepository.findEligibleKurrentBlocks());
+        when(blockQueryService.findManualKurrentBlocksByPerson(any(UUID.class)))
+                .thenAnswer(inv -> blockRepository.findManualKurrentBlocksByPerson(inv.getArgument(0)));
+        when(annotationService.findById(any(UUID.class)))
+                .thenAnswer(inv -> annotationRepository.findById(inv.getArgument(0)));
+        when(documentService.findById(any(UUID.class)))
+                .thenAnswer(inv -> documentRepository.findById(inv.getArgument(0)));
+        return new TrainingDataExportService(blockQueryService, annotationService, documentService, fileService);
+    }
+
     private UUID enrolledDoc(String filename) {
         Document doc = documentRepository.save(Document.builder()
                 .title(filename).originalFilename(filename).filePath(filename)