feat(training): add document-level training enrollment

- V29 migration: document_training_labels join table
- TrainingLabel enum: KURRENT_RECOGNITION, KURRENT_SEGMENTATION
- Document.trainingLabels @ElementCollection
- DocumentService.addTrainingLabel / removeTrainingLabel
- PATCH /api/documents/{id}/training-labels (WRITE_ALL)
- Auto-enroll on Kurrent OCR trigger (OcrService.startOcr)
- TranscriptionEditView: enrollment chips in panel footer
- JPQL queries updated to use MEMBER OF trainingLabels

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

backend/src/main/java/org/raddatz/familienarchiv/controller/DocumentController.java

@@ -21,6 +21,7 @@ import org.raddatz.familienarchiv.exception.ErrorCode;
 import org.raddatz.familienarchiv.model.Document;
 import org.raddatz.familienarchiv.dto.DocumentSort;
 import org.raddatz.familienarchiv.model.DocumentStatus;
+import org.raddatz.familienarchiv.model.TrainingLabel;
 import org.raddatz.familienarchiv.model.DocumentVersion;
 import org.raddatz.familienarchiv.security.Permission;
 import org.raddatz.familienarchiv.security.RequirePermission;
@@ -35,9 +36,11 @@ import org.springframework.core.io.InputStreamResource;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PatchMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RequestPart;
@@ -208,6 +211,29 @@ public class DocumentController {
         return ResponseEntity.ok(DocumentSearchResult.of(results));
     }
 
+    // --- TRAINING LABELS ---
+
+    public record TrainingLabelRequest(String label, boolean enrolled) {}
+
+    @PatchMapping("/{id}/training-labels")
+    @RequirePermission(Permission.WRITE_ALL)
+    public ResponseEntity<Void> patchTrainingLabel(
+            @PathVariable UUID id,
+            @RequestBody TrainingLabelRequest req) {
+        TrainingLabel label;
+        try {
+            label = TrainingLabel.valueOf(req.label());
+        } catch (IllegalArgumentException e) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Unknown training label: " + req.label());
+        }
+        if (req.enrolled()) {
+            documentService.addTrainingLabel(id, label);
+        } else {
+            documentService.removeTrainingLabel(id, label);
+        }
+        return ResponseEntity.noContent().build();
+    }
+
     // --- VERSIONS ---
 
     @GetMapping("/{id}/versions")

backend/src/main/java/org/raddatz/familienarchiv/model/Document.java

@@ -110,4 +110,11 @@ public class Document {
     @JoinTable(name = "document_tags", joinColumns = @JoinColumn(name = "document_id"), inverseJoinColumns = @JoinColumn(name = "tag_id"))
     @Builder.Default
     private Set<Tag> tags = new HashSet<>();
+
+    @ElementCollection(fetch = FetchType.EAGER)
+    @CollectionTable(name = "document_training_labels", joinColumns = @JoinColumn(name = "document_id"))
+    @Column(name = "label")
+    @Enumerated(EnumType.STRING)
+    @Builder.Default
+    private Set<TrainingLabel> trainingLabels = new HashSet<>();
 }

backend/src/main/java/org/raddatz/familienarchiv/model/TrainingLabel.java

@@ -0,0 +1,6 @@
+package org.raddatz.familienarchiv.model;
+
+public enum TrainingLabel {
+    KURRENT_RECOGNITION,
+    KURRENT_SEGMENTATION
+}

backend/src/main/java/org/raddatz/familienarchiv/repository/TranscriptionBlockRepository.java

@@ -2,6 +2,7 @@ package org.raddatz.familienarchiv.repository;
 
 import org.raddatz.familienarchiv.model.TranscriptionBlock;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 
 import java.util.List;
 import java.util.Optional;
@@ -14,4 +15,22 @@ public interface TranscriptionBlockRepository extends JpaRepository<Transcriptio
     Optional<TranscriptionBlock> findByIdAndDocumentId(UUID id, UUID documentId);
 
     int countByDocumentId(UUID documentId);
+
+    @Query("""
+            SELECT b FROM TranscriptionBlock b
+            JOIN DocumentAnnotation a ON a.id = b.annotationId
+            JOIN Document d ON d.id = b.documentId
+            WHERE (b.source = 'MANUAL' OR (b.source = 'OCR' AND b.reviewed = true))
+            AND 'KURRENT_RECOGNITION' MEMBER OF d.trainingLabels
+            """)
+    List<TranscriptionBlock> findEligibleKurrentBlocks();
+
+    @Query("""
+            SELECT b FROM TranscriptionBlock b
+            JOIN DocumentAnnotation a ON a.id = b.annotationId
+            JOIN Document d ON d.id = b.documentId
+            WHERE b.source = 'MANUAL' AND (b.text IS NULL OR b.text = '')
+            AND 'KURRENT_SEGMENTATION' MEMBER OF d.trainingLabels
+            """)
+    List<TranscriptionBlock> findSegmentationBlocks();
 }

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

@@ -9,6 +9,7 @@ import org.raddatz.familienarchiv.model.Document;
 import org.raddatz.familienarchiv.dto.DocumentSort;
 import org.raddatz.familienarchiv.model.DocumentStatus;
 import org.raddatz.familienarchiv.model.ScriptType;
+import org.raddatz.familienarchiv.model.TrainingLabel;
 import org.raddatz.familienarchiv.model.Person;
 import org.raddatz.familienarchiv.model.Tag;
 import org.raddatz.familienarchiv.repository.DocumentRepository;
@@ -385,6 +386,20 @@ public class DocumentService {
         documentRepository.save(doc);
     }
 
+    @Transactional
+    public void addTrainingLabel(UUID documentId, TrainingLabel label) {
+        Document doc = getDocumentById(documentId);
+        doc.getTrainingLabels().add(label);
+        documentRepository.save(doc);
+    }
+
+    @Transactional
+    public void removeTrainingLabel(UUID documentId, TrainingLabel label) {
+        Document doc = getDocumentById(documentId);
+        doc.getTrainingLabels().remove(label);
+        documentRepository.save(doc);
+    }
+
     public Document getDocumentById(UUID id) {
         return documentRepository.findById(id)
                 .orElseThrow(() -> DomainException.notFound(ErrorCode.DOCUMENT_NOT_FOUND, "Document not found: " + id));

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

@@ -66,6 +66,9 @@ public class OcrService {
 
         if (scriptTypeOverride != null) {
             documentService.updateScriptType(documentId, scriptTypeOverride);
+            if (scriptTypeOverride == ScriptType.HANDWRITING_KURRENT) {
+                documentService.addTrainingLabel(documentId, TrainingLabel.KURRENT_RECOGNITION);
+            }
         }
 
         OcrJob job = OcrJob.builder()

backend/src/main/resources/db/migration/V29__add_document_training_labels.sql

@@ -0,0 +1,5 @@
+CREATE TABLE document_training_labels (
+    document_id UUID NOT NULL REFERENCES documents(id) ON DELETE CASCADE,
+    label       VARCHAR(50) NOT NULL,
+    PRIMARY KEY (document_id, label)
+);