feat(timeline): add PersonService.getPersonsByGeneration + DocumentService.getAllForTimeline

PersonRepository.findByGeneration(Integer) — boxed to match nullable entity field.
DocumentRepository.findAllForTimeline() — Document.list entity-graph, single query.
Both services delegate with one-liner methods.

Refs #777
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -56,6 +56,11 @@ public interface DocumentRepository extends JpaRepository<Document, UUID>, JpaSp
     // Prüft effizient, ob ein Dateiname schon existiert (gibt true/false zurück)
     boolean existsByOriginalFilename(String originalFilename);
 
+    // Bulk-fetch for global timeline path — single query with sender+receivers eager-loaded.
+    @EntityGraph("Document.list")
+    @Query("SELECT d FROM Document d")
+    List<Document> findAllForTimeline();
+
     // lazy – @BatchSize(50) fallback active; see ADR-022
     @EntityGraph("Document.full")
     List<Document> findBySenderId(UUID senderId);

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

@@ -1051,6 +1051,10 @@ public class DocumentService {
         return documentRepository.findDocumentsWithoutVersions();
     }
 
+    public List<Document> getAllForTimeline() {
+        return documentRepository.findAllForTimeline();
+    }
+
     public List<Document> getDocumentsBySender(UUID senderId) {
         return documentRepository.findBySenderId(senderId);
     }

backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java

@@ -242,4 +242,7 @@ public interface PersonRepository extends JpaRepository<Person, UUID> {
               )
             """, nativeQuery = true)
     void insertMissingReceiverReference(@Param("source") UUID source, @Param("target") UUID target);
+
+    // Boxed Integer — matches the nullable person.generation column (primitive int would reject null rows).
+    List<Person> findByGeneration(Integer generation);
 }

backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java

@@ -210,6 +210,10 @@ public class PersonService {
         return personRepository.findByFamilyMemberTrueOrderByLastNameAscFirstNameAsc();
     }
 
+    public List<Person> getPersonsByGeneration(Integer generation) {
+        return personRepository.findByGeneration(generation);
+    }
+
     @Transactional
     public Person setFamilyMember(UUID personId, boolean familyMember) {
         Person person = getById(personId);

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

@@ -2943,4 +2943,17 @@ class DocumentServiceTest {
         assertThat(result.buckets()).isEmpty();
         verify(documentRepository, org.mockito.Mockito.never()).findAll(any(Specification.class));
     }
+
+    // --- getAllForTimeline ---
+
+    @Test
+    void getAllForTimeline_delegates_bulk_fetch_to_repository() {
+        Document doc = Document.builder().id(UUID.randomUUID()).title("Brief").build();
+        when(documentRepository.findAllForTimeline()).thenReturn(List.of(doc));
+
+        List<Document> result = documentService.getAllForTimeline();
+
+        assertThat(result).containsExactly(doc);
+        verify(documentRepository).findAllForTimeline();
+    }
 }

backend/src/test/java/org/raddatz/familienarchiv/person/PersonServiceTest.java

@@ -1105,4 +1105,25 @@ class PersonServiceTest {
         assertThat(result.direct()).hasSize(1);
         assertThat(result.partial()).isEmpty();
     }
+
+    // --- getPersonsByGeneration ---
+
+    @Test
+    void getPersonsByGeneration_delegates_to_repository() {
+        Person p = Person.builder().id(UUID.randomUUID()).lastName("Müller").generation(2).build();
+        when(personRepository.findByGeneration(2)).thenReturn(List.of(p));
+
+        List<Person> result = personService.getPersonsByGeneration(2);
+
+        assertThat(result).containsExactly(p);
+    }
+
+    @Test
+    void getPersonsByGeneration_returns_emptyList_when_no_match() {
+        when(personRepository.findByGeneration(99)).thenReturn(List.of());
+
+        List<Person> result = personService.getPersonsByGeneration(99);
+
+        assertThat(result).isEmpty();
+    }
 }