test(document): add @SpringBootTest smoke tests for lazy-loading correctness

Five integration tests verify that DocumentService and DashboardService
do not throw LazyInitializationException after the EAGER→LAZY migration:
getDocumentById, getRecentActivity, searchDocuments (receiver/sender sort),
and dashboardService.getResume.

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

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

@@ -0,0 +1,158 @@
+package org.raddatz.familienarchiv.document;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.audit.AuditLogQueryService;
+import org.raddatz.familienarchiv.dashboard.DashboardService;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.raddatz.familienarchiv.tag.TagRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+class DocumentLazyLoadingTest {
+
+    @MockitoBean
+    S3Client s3Client;
+
+    @Autowired
+    DocumentRepository documentRepository;
+
+    @Autowired
+    PersonRepository personRepository;
+
+    @Autowired
+    TagRepository tagRepository;
+
+    @Autowired
+    DocumentService documentService;
+
+    @Autowired
+    DashboardService dashboardService;
+
+    @MockitoBean
+    AuditLogQueryService auditLogQueryService;
+
+    @AfterEach
+    void cleanup() {
+        documentRepository.deleteAll();
+        tagRepository.deleteAll();
+        personRepository.deleteAll();
+    }
+
+    @Test
+    void getDocumentById_tagsAndReceiversAccessible_afterReturnFromService() {
+        Person sender = personRepository.save(Person.builder().firstName("Max").lastName("LzSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("LzReceiver").build());
+        Tag tag = tagRepository.save(Tag.builder().name("LzTag").build());
+        Document doc = documentRepository.save(Document.builder()
+                .title("LazyTest").originalFilename("lazy_test.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        Document result = documentService.getDocumentById(doc.getId());
+
+        assertThatCode(() -> {
+            assertThat(result.getTags()).isNotEmpty();
+            result.getTags().forEach(t -> assertThat(t.getName()).isNotNull());
+            assertThat(result.getReceivers()).isNotEmpty();
+            result.getReceivers().forEach(r -> assertThat(r.getLastName()).isNotNull());
+        }).doesNotThrowAnyException();
+    }
+
+    @Test
+    void getRecentActivity_doesNotThrowLazyInitializationException() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("RaSender").build());
+        Tag tag = tagRepository.save(Tag.builder().name("RaTag").build());
+        for (int i = 0; i < 3; i++) {
+            documentRepository.save(Document.builder()
+                    .title("RaDoc " + i).originalFilename("ra_doc" + i + ".pdf")
+                    .status(DocumentStatus.UPLOADED)
+                    .sender(sender)
+                    .tags(new HashSet<>(Set.of(tag)))
+                    .build());
+        }
+
+        assertThatCode(() -> documentService.getRecentActivity(3))
+                .doesNotThrowAnyException();
+    }
+
+    @Test
+    void searchDocuments_receiverSort_doesNotThrowLazyInitializationException() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("SrSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("SrReceiver").build());
+        Tag tag = tagRepository.save(Tag.builder().name("SrTag").build());
+        documentRepository.save(Document.builder()
+                .title("SrDoc").originalFilename("sr_doc.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        assertThatCode(() -> documentService.searchDocuments(
+                null, null, null, null, null, null, null, null,
+                DocumentSort.RECEIVER, "asc", null,
+                PageRequest.of(0, 20)))
+                .doesNotThrowAnyException();
+    }
+
+    @Test
+    void searchDocuments_senderSort_doesNotThrowLazyInitializationException() {
+        Person sender = personRepository.save(Person.builder().firstName("Hans").lastName("SsSender").build());
+        Tag tag = tagRepository.save(Tag.builder().name("SsTag").build());
+        documentRepository.save(Document.builder()
+                .title("SsDoc").originalFilename("ss_doc.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .tags(new HashSet<>(Set.of(tag)))
+                .build());
+
+        assertThatCode(() -> documentService.searchDocuments(
+                null, null, null, null, null, null, null, null,
+                DocumentSort.SENDER, "asc", null,
+                PageRequest.of(0, 20)))
+                .doesNotThrowAnyException();
+    }
+
+    @Test
+    void dashboardService_getResume_accessesReceiversViaGetDocumentById_withoutException() {
+        Person sender = personRepository.save(Person.builder().firstName("Max").lastName("DsSender").build());
+        Person receiver = personRepository.save(Person.builder().firstName("Anna").lastName("DsReceiver").build());
+        Document doc = documentRepository.save(Document.builder()
+                .title("DashboardTest").originalFilename("dashboard_test.pdf")
+                .status(DocumentStatus.UPLOADED)
+                .sender(sender)
+                .receivers(new HashSet<>(Set.of(receiver)))
+                .build());
+        UUID fakeUserId = UUID.randomUUID();
+        when(auditLogQueryService.findMostRecentDocumentForUser(any())).thenReturn(Optional.of(doc.getId()));
+        when(auditLogQueryService.findRecentContributorsPerDocument(any())).thenReturn(java.util.Map.of());
+
+        assertThatCode(() -> dashboardService.getResume(fakeUserId))
+                .doesNotThrowAnyException();
+    }
+}