fix(ocr): replace IllegalStateException with DomainException.internal in triggerManualSenderTraining

Ensures the unexpected-state path produces a structured JSON error response
instead of an unmapped 500 RuntimeException. Adds OCR_TRAINING_CONFLICT
ErrorCode and mirrors it in the frontend errors.ts. Adds coverage tests for
getAllSenderModels() and runSenderTraining().

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

backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java

@@ -77,6 +77,8 @@ public enum ErrorCode {
     OCR_PROCESSING_FAILED,
     /** A training run is already in progress. 409 */
     TRAINING_ALREADY_RUNNING,
+    /** Internal inconsistency: expected training run row was not found after creation. 500 */
+    OCR_TRAINING_CONFLICT,
 
     // --- Tags ---
     /** A tag with the given ID does not exist. 404 */

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

@@ -2,6 +2,8 @@ package org.raddatz.familienarchiv.service;
 
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
 import org.raddatz.familienarchiv.model.OcrTrainingRun;
 import org.raddatz.familienarchiv.model.SenderModel;
 import org.raddatz.familienarchiv.model.TrainingStatus;
@@ -64,8 +66,9 @@ public class SenderModelService {
         boolean runNow = runOrQueueSenderTraining(personId, (int) correctedLines);
         TrainingStatus targetStatus = runNow ? TrainingStatus.RUNNING : TrainingStatus.QUEUED;
         OcrTrainingRun run = trainingRunRepository.findFirstByPersonIdAndStatus(personId, targetStatus)
-                .orElseThrow(() -> new IllegalStateException(
-                        "Expected " + targetStatus + " row for person " + personId));
+                .orElseThrow(() -> DomainException.internal(
+                        ErrorCode.OCR_TRAINING_CONFLICT,
+                        "Expected " + targetStatus + " run for person " + personId));
         if (runNow) {
             self.runSenderTraining(personId);
         }

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

@@ -64,6 +64,38 @@ class SenderModelServiceTest {
         ReflectionTestUtils.setField(service, "retrainDelta", 50);
     }
 
+    // ─── getAllSenderModels ───────────────────────────────────────────────────
+
+    @Test
+    void getAllSenderModels_returnsAllModelsFromRepository() {
+        SenderModel model = SenderModel.builder()
+                .id(UUID.randomUUID()).personId(personId).correctedLinesAtTraining(100).build();
+        when(senderModelRepository.findAll()).thenReturn(java.util.List.of(model));
+
+        java.util.List<SenderModel> result = service.getAllSenderModels();
+
+        assertThat(result).hasSize(1);
+        assertThat(result.get(0).getPersonId()).isEqualTo(personId);
+    }
+
+    // ─── runSenderTraining ────────────────────────────────────────────────────
+
+    @Test
+    void runSenderTraining_queriesBlockCountForPerson() {
+        when(blockRepository.countManualKurrentBlocksByPerson(personId)).thenReturn(42L);
+        // triggerSenderTraining needs a RUNNING row — return empty to abort early
+        when(trainingRunRepository.findFirstByPersonIdAndStatus(personId, TrainingStatus.RUNNING))
+                .thenReturn(Optional.empty());
+
+        try {
+            service.runSenderTraining(personId);
+        } catch (Exception ignored) {
+            // triggerSenderTraining will throw when no RUNNING row found
+        }
+
+        verify(blockRepository).countManualKurrentBlocksByPerson(personId);
+    }
+
     // ─── Activation threshold ─────────────────────────────────────────────────
 
     @Test
@@ -318,6 +350,25 @@ class SenderModelServiceTest {
                 .isInstanceOf(DomainException.class);
     }
 
+    @Test
+    void triggerManualSenderTraining_throwsDomainException_whenRunRowMissingAfterCreate() {
+        when(personService.getById(personId)).thenReturn(Person.builder().id(personId).build());
+        when(blockRepository.countManualKurrentBlocksByPerson(personId)).thenReturn(0L);
+        when(trainingRunRepository.existsByPersonIdAndStatus(personId, TrainingStatus.QUEUED)).thenReturn(false);
+        when(trainingRunRepository.findFirstByStatus(TrainingStatus.RUNNING)).thenReturn(Optional.empty());
+        OcrTrainingRun runningRun = OcrTrainingRun.builder()
+                .id(UUID.randomUUID()).status(TrainingStatus.RUNNING)
+                .personId(personId).blockCount(0).documentCount(0).modelName("sender_" + personId).build();
+        when(trainingRunRepository.save(any())).thenReturn(runningRun);
+        // Simulate the run row not being found after creation (defensive path)
+        when(trainingRunRepository.findFirstByPersonIdAndStatus(personId, TrainingStatus.RUNNING))
+                .thenReturn(Optional.empty());
+
+        org.assertj.core.api.Assertions.assertThatThrownBy(
+                () -> service.triggerManualSenderTraining(personId))
+                .isInstanceOf(DomainException.class);
+    }
+
     @Test
     void triggerSenderTraining_promotesNextQueued_afterCompletion() throws Exception {
         UUID nextPersonId = UUID.randomUUID();

frontend/src/lib/errors.ts

@@ -27,6 +27,7 @@ export type ErrorCode =
 	| 'OCR_DOCUMENT_NOT_UPLOADED'
 	| 'OCR_PROCESSING_FAILED'
 	| 'TRAINING_ALREADY_RUNNING'
+	| 'OCR_TRAINING_CONFLICT'
 	| 'INVALID_TAG_COLOR'
 	| 'TAG_CYCLE_DETECTED'
 	| 'TAG_NOT_FOUND'
@@ -105,6 +106,8 @@ export function getErrorMessage(code: ErrorCode | string | undefined): string {
 			return m.error_ocr_processing_failed();
 		case 'TRAINING_ALREADY_RUNNING':
 			return m.error_training_already_running();
+		case 'OCR_TRAINING_CONFLICT':
+			return m.error_internal_error();
 		case 'INVALID_TAG_COLOR':
 			return m.error_invalid_tag_color();
 		case 'TAG_CYCLE_DETECTED':