test(activity): assert Chronik rows never fabricate a letter date

Negative guarantee for #668: ChronikRow renders the activity timestamp
(happenedAt), and ActivityFeedItemDTO carries no document-date surface, so
no undated badge or "Datum unbekannt" letter-date label may appear. Pins
this as a regression fixture so a future change can't quietly add a date
chip to the activity feed.

Refs #668

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

@@ -313,9 +313,10 @@ public class DocumentController {
             @RequestParam(required = false) String tagQ,
             @RequestParam(required = false) DocumentStatus status,
             @RequestParam(required = false) String tagOp,
+            @RequestParam(required = false) Boolean undated,
             Authentication authentication) {
         TagOperator operator = "OR".equalsIgnoreCase(tagOp) ? TagOperator.OR : TagOperator.AND;
-        List<UUID> ids = documentService.findIdsForFilter(q, from, to, senderId, receiverId, tags, tagQ, status, operator);
+        List<UUID> ids = documentService.findIdsForFilter(q, from, to, senderId, receiverId, tags, tagQ, status, operator, Boolean.TRUE.equals(undated));
         if (ids.size() > BULK_EDIT_FILTER_MAX_IDS) {
             throw DomainException.badRequest(ErrorCode.BULK_EDIT_TOO_MANY_IDS,
                     "Filter matches " + ids.size() + " documents — refine filter (max " + BULK_EDIT_FILTER_MAX_IDS + ")");
@@ -375,6 +376,7 @@ public class DocumentController {
             @Parameter(description = "Sort field") @RequestParam(required = false) DocumentSort sort,
             @Parameter(description = "Sort direction: ASC or DESC") @RequestParam(required = false, defaultValue = "DESC") String dir,
             @Parameter(description = "Tag operator: AND (default) or OR") @RequestParam(required = false) String tagOp,
+            @Parameter(description = "Restrict to undated documents (meta_date IS NULL)") @RequestParam(required = false) Boolean undated,
             // @Max on page guards against overflow when pageable.getOffset() is computed
             // as page * size — Integer.MAX_VALUE * 50 would wrap to a negative long, which
             // Hibernate cheerfully turns into an invalid SQL OFFSET.
@@ -387,7 +389,7 @@ public class DocumentController {
         // defaults to AND, which matches the frontend default and keeps old clients working.
         TagOperator operator = "OR".equalsIgnoreCase(tagOp) ? TagOperator.OR : TagOperator.AND;
         Pageable pageable = PageRequest.of(page, size);
-        return ResponseEntity.ok(documentService.searchDocuments(q, from, to, senderId, receiverId, tags, tagQ, status, sort, dir, operator, pageable));
+        return ResponseEntity.ok(documentService.searchDocuments(q, from, to, senderId, receiverId, tags, tagQ, status, sort, dir, operator, Boolean.TRUE.equals(undated), pageable));
     }
 
     @GetMapping(value = "/density", produces = MediaType.APPLICATION_JSON_VALUE)

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

@@ -171,7 +171,7 @@ public class DocumentService {
                 hasFts, ftsIds, null, null,
                 filters.sender(), filters.receiver(),
                 filters.tags(), filters.tagQ(),
-                filters.status(), filters.tagOperator());
+                filters.status(), filters.tagOperator(), false);
         return documentRepository.findAll(spec).stream()
                 .map(Document::getDocumentDate)
                 .filter(Objects::nonNull)
@@ -501,7 +501,8 @@ public class DocumentService {
      */
     @Transactional(readOnly = true)
     public List<UUID> findIdsForFilter(String text, LocalDate from, LocalDate to, UUID sender, UUID receiver,
-                                       List<String> tags, String tagQ, DocumentStatus status, TagOperator tagOperator) {
+                                       List<String> tags, String tagQ, DocumentStatus status, TagOperator tagOperator,
+                                       boolean undated) {
         boolean hasText = StringUtils.hasText(text);
         List<UUID> rankedIds = null;
         if (hasText) {
@@ -510,7 +511,7 @@ public class DocumentService {
         }
 
         Specification<Document> spec = buildSearchSpec(
-                hasText, rankedIds, from, to, sender, receiver, tags, tagQ, status, tagOperator);
+                hasText, rankedIds, from, to, sender, receiver, tags, tagQ, status, tagOperator, undated);
         return documentRepository.findAll(spec).stream().map(Document::getId).toList();
     }
 
@@ -524,7 +525,8 @@ public class DocumentService {
                                                     LocalDate from, LocalDate to,
                                                     UUID sender, UUID receiver,
                                                     List<String> tags, String tagQ,
-                                                    DocumentStatus status, TagOperator tagOperator) {
+                                                    DocumentStatus status, TagOperator tagOperator,
+                                                    boolean undated) {
         boolean useOrLogic = tagOperator == TagOperator.OR;
         List<Set<UUID>> expandedTagSets = tagService.expandTagNamesToDescendantIdSets(tags);
         Specification<Document> textSpec = hasText ? hasIds(ftsIds) : (root, query, cb) -> null;
@@ -534,7 +536,8 @@ public class DocumentService {
                 .and(hasReceiver(receiver))
                 .and(hasTags(expandedTagSets, useOrLogic))
                 .and(hasTagPartial(tagQ))
-                .and(hasStatus(status));
+                .and(hasStatus(status))
+                .and(undatedOnly(undated));
     }
 
     /**
@@ -663,11 +666,13 @@ public class DocumentService {
     }
 
     // 1. Allgemeine Suche (für das Suchfeld im Frontend)
-    public DocumentSearchResult searchDocuments(String text, LocalDate from, LocalDate to, UUID sender, UUID receiver, List<String> tags, String tagQ, DocumentStatus status, DocumentSort sort, String dir, TagOperator tagOperator, Pageable pageable) {
+    public DocumentSearchResult searchDocuments(String text, LocalDate from, LocalDate to, UUID sender, UUID receiver, List<String> tags, String tagQ, DocumentStatus status, DocumentSort sort, String dir, TagOperator tagOperator, boolean undated, Pageable pageable) {
         boolean hasText = StringUtils.hasText(text);
 
         // Pure-text RELEVANCE: push pagination into SQL — skip findAllMatchingIdsByFts entirely (ADR-008).
-        if (isPureTextRelevance(hasText, sort, from, to, sender, receiver, tags, tagQ, status)) {
+        // An active undated filter must NOT take this path: it bypasses buildSearchSpec, so the
+        // undatedOnly predicate would be silently dropped.
+        if (!undated && isPureTextRelevance(hasText, sort, from, to, sender, receiver, tags, tagQ, status)) {
             return relevanceSortedPageFromSql(text, pageable);
         }
 
@@ -678,7 +683,7 @@ public class DocumentService {
         }
 
         Specification<Document> spec = buildSearchSpec(
-                hasText, rankedIds, from, to, sender, receiver, tags, tagQ, status, tagOperator);
+                hasText, rankedIds, from, to, sender, receiver, tags, tagQ, status, tagOperator, undated);
 
         // SENDER and RECEIVER sorts load the full match set and slice in-memory.
         // JPA's Sort.by("sender.lastName") generates an INNER JOIN that silently drops
@@ -797,10 +802,17 @@ public class DocumentService {
         return transcriptionBlockQueryService.getCompletionStats(docIds);
     }
 
-    private Sort resolveSort(DocumentSort sort, String dir) {
+    Sort resolveSort(DocumentSort sort, String dir) {
         Sort.Direction direction = "ASC".equalsIgnoreCase(dir) ? Sort.Direction.ASC : Sort.Direction.DESC;
         if (sort == null || sort == DocumentSort.DATE || sort == DocumentSort.RELEVANCE) {
-            return Sort.by(direction, "documentDate");
+            // Undated documents (null documentDate) must order last regardless of
+            // direction — Postgres puts NULLs FIRST on ASC by default, which would
+            // surface the undated pile at the top with no explanation (issue #668).
+            // The createdAt tiebreaker gives a stable total order when every row is
+            // null-dated (the "Nur undatierte" filter), so pagination is deterministic.
+            return Sort.by(
+                    new Sort.Order(direction, "documentDate").nullsLast(),
+                    Sort.Order.asc("createdAt"));
         }
         // SENDER and RECEIVER are sorted in-memory before this method is called
         return switch (sort) {

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

@@ -55,6 +55,12 @@ public class DocumentSpecifications {
         return (root, query, cb) -> status == null ? null : cb.equal(root.get("status"), status);
     }
 
+    // Filtert auf undatierte Dokumente (meta_date IS NULL) — für die "Nur undatierte"-Triage.
+    // false → kein Prädikat (no-op), true → documentDate IS NULL (issue #668).
+    public static Specification<Document> undatedOnly(boolean undated) {
+        return (root, query, cb) -> undated ? cb.isNull(root.get("documentDate")) : null;
+    }
+
     /**
      * Filtert nach vorausgeweiteten Tag-ID-Sets mit AND- oder OR-Logik.
      *

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

@@ -1,6 +1,7 @@
 package org.raddatz.familienarchiv.document;
 
 import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
 import org.raddatz.familienarchiv.document.DocumentBatchMetadataDTO;
 import org.raddatz.familienarchiv.document.DocumentSearchResult;
 import org.raddatz.familienarchiv.document.DocumentVersionSummary;
@@ -35,7 +36,9 @@ import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.verify;
@@ -73,23 +76,69 @@ class DocumentControllerTest {
     @Test
     @WithMockUser
     void search_returns200_whenAuthenticated() throws Exception {
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of()));
 
         mockMvc.perform(get("/api/documents/search"))
                 .andExpect(status().isOk());
     }
 
+    @Test
+    @WithMockUser
+    void search_undatedTrue_isReachableByAuthenticatedUser() throws Exception {
+        // The read GET must stay reachable for READ_ALL users — guards against a
+        // future refactor accidentally write-guarding the undated triage path (#668).
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
+                .thenReturn(DocumentSearchResult.of(List.of()));
+
+        mockMvc.perform(get("/api/documents/search").param("undated", "true"))
+                .andExpect(status().isOk());
+    }
+
+    @Test
+    void search_undatedTrue_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(get("/api/documents/search").param("undated", "true"))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser
+    void search_undatedTrue_isForwardedToServiceAsTrue() throws Exception {
+        ArgumentCaptor<Boolean> undatedCaptor = ArgumentCaptor.forClass(Boolean.class);
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
+                .thenReturn(DocumentSearchResult.of(List.of()));
+
+        mockMvc.perform(get("/api/documents/search").param("undated", "true"))
+                .andExpect(status().isOk());
+
+        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), undatedCaptor.capture(), any());
+        assertThat(undatedCaptor.getValue()).isTrue();
+    }
+
+    @Test
+    @WithMockUser
+    void search_withoutUndatedParam_forwardsFalseToService() throws Exception {
+        ArgumentCaptor<Boolean> undatedCaptor = ArgumentCaptor.forClass(Boolean.class);
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
+                .thenReturn(DocumentSearchResult.of(List.of()));
+
+        mockMvc.perform(get("/api/documents/search"))
+                .andExpect(status().isOk());
+
+        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), undatedCaptor.capture(), any());
+        assertThat(undatedCaptor.getValue()).isFalse();
+    }
+
     @Test
     @WithMockUser
     void search_withStatusParam_passesItToService() throws Exception {
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), eq(DocumentStatus.REVIEWED), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), eq(DocumentStatus.REVIEWED), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of()));
 
         mockMvc.perform(get("/api/documents/search").param("status", "REVIEWED"))
                 .andExpect(status().isOk());
 
-        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), eq(DocumentStatus.REVIEWED), any(), any(), any(), any());
+        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), eq(DocumentStatus.REVIEWED), any(), any(), any(), anyBoolean(), any());
     }
 
     @Test
@@ -116,7 +165,7 @@ class DocumentControllerTest {
     @Test
     @WithMockUser
     void search_responseContainsTotalCount() throws Exception {
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of()));
 
         mockMvc.perform(get("/api/documents/search"))
@@ -131,7 +180,7 @@ class DocumentControllerTest {
         UUID docId = UUID.randomUUID();
         var matchData = new SearchMatchData(
                 "Er schrieb einen langen Brief", List.of(), false, List.of(), List.of(), List.of(), null, List.of());
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of(new DocumentListItem(
                         docId, "Brief an Anna", "brief.pdf", null, null,
                         DatePrecision.UNKNOWN, null, null,
@@ -150,7 +199,7 @@ class DocumentControllerTest {
     void search_returns_flat_item_with_id_and_without_sensitive_fields() throws Exception {
         UUID docId = UUID.randomUUID();
         var matchData = new SearchMatchData(null, List.of(), false, List.of(), List.of(), List.of(), null, List.of());
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of(new DocumentListItem(
                         docId, "Brief an Anna", "brief.pdf", null, null,
                         DatePrecision.UNKNOWN, null, null,
@@ -172,7 +221,7 @@ class DocumentControllerTest {
     @Test
     @WithMockUser
     void search_responseExposesPagingFields() throws Exception {
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of()));
 
         mockMvc.perform(get("/api/documents/search"))
@@ -217,7 +266,7 @@ class DocumentControllerTest {
     @Test
     @WithMockUser
     void search_passesPageRequestToService() throws Exception {
-        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), any()))
                 .thenReturn(DocumentSearchResult.of(List.of()));
 
         mockMvc.perform(get("/api/documents/search").param("page", "2").param("size", "25"))
@@ -225,7 +274,7 @@ class DocumentControllerTest {
 
         org.mockito.ArgumentCaptor<org.springframework.data.domain.Pageable> captor =
                 org.mockito.ArgumentCaptor.forClass(org.springframework.data.domain.Pageable.class);
-        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), captor.capture());
+        verify(documentService).searchDocuments(any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean(), captor.capture());
         org.springframework.data.domain.Pageable pageable = captor.getValue();
         org.assertj.core.api.Assertions.assertThat(pageable.getPageNumber()).isEqualTo(2);
         org.assertj.core.api.Assertions.assertThat(pageable.getPageSize()).isEqualTo(25);
@@ -1143,7 +1192,7 @@ class DocumentControllerTest {
     void getDocumentIds_returns200_andDelegatesToService() throws Exception {
         when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
         UUID id = UUID.randomUUID();
-        when(documentService.findIdsForFilter(any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.findIdsForFilter(any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean()))
                 .thenReturn(List.of(id));
 
         mockMvc.perform(get("/api/documents/ids"))
@@ -1156,13 +1205,13 @@ class DocumentControllerTest {
     void getDocumentIds_passesSenderIdParamToService() throws Exception {
         when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
         UUID senderId = UUID.randomUUID();
-        when(documentService.findIdsForFilter(any(), any(), any(), eq(senderId), any(), any(), any(), any(), any()))
+        when(documentService.findIdsForFilter(any(), any(), any(), eq(senderId), any(), any(), any(), any(), any(), anyBoolean()))
                 .thenReturn(List.of());
 
         mockMvc.perform(get("/api/documents/ids").param("senderId", senderId.toString()))
                 .andExpect(status().isOk());
 
-        verify(documentService).findIdsForFilter(any(), any(), any(), eq(senderId), any(), any(), any(), any(), any());
+        verify(documentService).findIdsForFilter(any(), any(), any(), eq(senderId), any(), any(), any(), any(), any(), anyBoolean());
     }
 
     @Test
@@ -1172,7 +1221,7 @@ class DocumentControllerTest {
         // Service returns 5001 IDs — one over BULK_EDIT_FILTER_MAX_IDS (5000).
         java.util.List<UUID> tooMany = new java.util.ArrayList<>(5001);
         for (int i = 0; i < 5001; i++) tooMany.add(UUID.randomUUID());
-        when(documentService.findIdsForFilter(any(), any(), any(), any(), any(), any(), any(), any(), any()))
+        when(documentService.findIdsForFilter(any(), any(), any(), any(), any(), any(), any(), any(), any(), anyBoolean()))
                 .thenReturn(tooMany);
 
         mockMvc.perform(get("/api/documents/ids"))

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

@@ -123,8 +123,7 @@ class DocumentLazyLoadingTest {
 
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.RECEIVER, "asc", null,
-                PageRequest.of(0, 20));
+                DocumentSort.RECEIVER, "asc", null, false, PageRequest.of(0, 20));
         assertThat(result.totalElements()).isGreaterThan(0);
         assertThatCode(() ->
                 result.items().forEach(i -> { if (i.sender() != null) i.sender().getLastName(); }))
@@ -139,8 +138,7 @@ class DocumentLazyLoadingTest {
 
         assertThatCode(() -> documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.SENDER, "asc", null,
-                PageRequest.of(0, 20)))
+                DocumentSort.SENDER, "asc", null, false, PageRequest.of(0, 20)))
                 .doesNotThrowAnyException();
     }
 

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

@@ -56,8 +56,7 @@ class DocumentListItemIntegrationTest {
 
         assertThatCode(() -> documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(0, 50)))
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(0, 50)))
             .doesNotThrowAnyException();
     }
 
@@ -72,8 +71,7 @@ class DocumentListItemIntegrationTest {
 
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(0, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(0, 50));
 
         assertThat(result.totalElements()).isGreaterThan(0);
         DocumentListItem item = result.items().get(0);
@@ -94,8 +92,7 @@ class DocumentListItemIntegrationTest {
 
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(0, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(0, 50));
 
         DocumentListItem item = result.items().stream()
                 .filter(i -> i.title().equals("Range Brief")).findFirst().orElseThrow();

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

@@ -62,8 +62,7 @@ class DocumentSearchPagedIntegrationTest {
     void search_firstPage_returnsExactlyPageSizeItems_andCorrectTotalElements() {
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(0, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(0, 50));
 
         assertThat(result.items()).hasSize(50);
         assertThat(result.totalElements()).isEqualTo(FIXTURE_SIZE);
@@ -76,8 +75,7 @@ class DocumentSearchPagedIntegrationTest {
     void search_lastPartialPage_returnsRemainingItems() {
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(2, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(2, 50));
 
         // Page 2 (offset 100) of 120 docs → exactly 20 items on the tail.
         assertThat(result.items()).hasSize(20);
@@ -89,8 +87,7 @@ class DocumentSearchPagedIntegrationTest {
     void search_pageBeyondLast_returnsEmptyContent_totalElementsStillCorrect() {
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(99, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(99, 50));
 
         assertThat(result.items()).isEmpty();
         assertThat(result.totalElements()).isEqualTo(FIXTURE_SIZE);
@@ -103,8 +100,7 @@ class DocumentSearchPagedIntegrationTest {
         // returns the correct total from a real repository fetch.
         DocumentSearchResult result = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.SENDER, "asc", null,
-                PageRequest.of(1, 50));
+                DocumentSort.SENDER, "asc", null, false, PageRequest.of(1, 50));
 
         assertThat(result.items()).hasSize(50);
         assertThat(result.totalElements()).isEqualTo(FIXTURE_SIZE);
@@ -116,12 +112,10 @@ class DocumentSearchPagedIntegrationTest {
     void search_differentPagesReturnDisjointSlices() {
         DocumentSearchResult page0 = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(0, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(0, 50));
         DocumentSearchResult page1 = documentService.searchDocuments(
                 null, null, null, null, null, null, null, null,
-                DocumentSort.DATE, "DESC", null,
-                PageRequest.of(1, 50));
+                DocumentSort.DATE, "DESC", null, false, PageRequest.of(1, 50));
 
         // No document id should appear on both pages — slicing must be exclusive.
         var idsOnPage0 = page0.items().stream()

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

@@ -67,7 +67,7 @@ class DocumentServiceSortTest {
                 .thenReturn(new PageImpl<>(List.of(newer, older)));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, DocumentSort.DATE, "DESC", null, PAGE);
+                "Brief", null, null, null, null, null, null, null, DocumentSort.DATE, "DESC", null, false, PAGE);
 
         assertThat(result.items()).hasSize(2);
         assertThat(result.items().get(0).id()).isEqualTo(id2);  // newer first
@@ -84,7 +84,7 @@ class DocumentServiceSortTest {
                 .thenReturn(List.of(doc(id1)));
 
         documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, PAGE);
+                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, false, PAGE);
 
         verify(documentRepository).findFtsPageRaw(anyString(), anyInt(), anyInt());
         verify(documentRepository, never()).findAllMatchingIdsByFts(anyString());
@@ -102,7 +102,7 @@ class DocumentServiceSortTest {
         when(documentRepository.findAllById(any())).thenReturn(List.of(doc(id2), doc(id1))); // unordered from JPA
 
         DocumentSearchResult result = documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, PAGE);
+                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, false, PAGE);
 
         assertThat(result.items().get(0).id()).isEqualTo(id1);
     }
@@ -119,7 +119,7 @@ class DocumentServiceSortTest {
         when(documentRepository.findAllById(any())).thenReturn(List.of(doc(id2), doc(id1)));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, null, null, null, PAGE);
+                "Brief", null, null, null, null, null, null, null, null, null, null, false, PAGE);
 
         assertThat(result.items().get(0).id()).isEqualTo(id1);
     }
@@ -133,7 +133,7 @@ class DocumentServiceSortTest {
 
         DocumentSearchResult result = documentService.searchDocuments(
                 "Brief", null, null, null, null, null, null, null,
-                DocumentSort.RELEVANCE, null, null, hugePage);
+                DocumentSort.RELEVANCE, null, null, false, hugePage);
 
         assertThat(result.items()).isEmpty();
         verify(documentRepository, never()).findFtsPageRaw(anyString(), anyInt(), anyInt());
@@ -153,7 +153,7 @@ class DocumentServiceSortTest {
 
         DocumentSearchResult result = documentService.searchDocuments(
                 "Brief", null, null, null, null, null, null, null,
-                DocumentSort.RELEVANCE, null, null, PAGE);
+                DocumentSort.RELEVANCE, null, null, false, PAGE);
 
         assertThat(result.items()).hasSize(1);
         assertThat(result.items().get(0).id()).isEqualTo(uuidId);
@@ -173,7 +173,7 @@ class DocumentServiceSortTest {
         // sender filter is active → triggers in-memory path, not findFtsPageRaw
         LocalDate from = LocalDate.of(1900, 1, 1);
         documentService.searchDocuments(
-                "Brief", from, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, PAGE);
+                "Brief", from, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, false, PAGE);
 
         verify(documentRepository, never()).findFtsPageRaw(anyString(), anyInt(), anyInt());
         verify(documentRepository).findAllMatchingIdsByFts("Brief");

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

@@ -47,6 +47,8 @@ import java.util.UUID;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.isNull;
 import static org.mockito.Mockito.*;
@@ -1409,8 +1411,7 @@ class DocumentServiceTest {
                 .thenReturn(new PageImpl<>(List.of()));
 
         documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null,
-                org.springframework.data.domain.PageRequest.of(1, 50));
+                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null, false, org.springframework.data.domain.PageRequest.of(1, 50));
 
         verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class));
         verify(documentRepository, never()).findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Sort.class));
@@ -1423,8 +1424,7 @@ class DocumentServiceTest {
                 .thenReturn(new PageImpl<>(List.of()));
 
         documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null,
-                org.springframework.data.domain.PageRequest.of(3, 25));
+                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null, false, org.springframework.data.domain.PageRequest.of(3, 25));
 
         verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), captor.capture());
         assertThat(captor.getValue().getPageNumber()).isEqualTo(3);
@@ -1440,8 +1440,7 @@ class DocumentServiceTest {
                 .thenReturn(new PageImpl<>(List.of(d), org.springframework.data.domain.PageRequest.of(0, 50), 120L));
 
         DocumentSearchResult result = documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null,
-                org.springframework.data.domain.PageRequest.of(0, 50));
+                org.raddatz.familienarchiv.document.DocumentSort.DATE, "DESC", null, false, org.springframework.data.domain.PageRequest.of(0, 50));
 
         assertThat(result.totalElements()).isEqualTo(120L);
         assertThat(result.pageNumber()).isZero();
@@ -1450,6 +1449,40 @@ class DocumentServiceTest {
         assertThat(result.items()).hasSize(1); // only the slice is enriched
     }
 
+    @Test
+    void searchDocuments_dateSort_DESC_ordersUndatedLast() {
+        ArgumentCaptor<Pageable> captor = ArgumentCaptor.forClass(Pageable.class);
+        when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class)))
+                .thenReturn(new PageImpl<>(List.of()));
+
+        documentService.searchDocuments(null, null, null, null, null, null, null, null,
+                DocumentSort.DATE, "DESC", null, false, org.springframework.data.domain.PageRequest.of(0, 5));
+
+        verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), captor.capture());
+        Sort.Order dateOrder = captor.getValue().getSort().getOrderFor("documentDate");
+        assertThat(dateOrder).isNotNull();
+        assertThat(dateOrder.getDirection()).isEqualTo(Sort.Direction.DESC);
+        assertThat(dateOrder.getNullHandling()).isEqualTo(Sort.NullHandling.NULLS_LAST);
+    }
+
+    @Test
+    void searchDocuments_dateSort_ASC_ordersUndatedLast() {
+        // The ASC bug: Postgres puts NULLs FIRST on ascending sort without explicit
+        // NULLS LAST, surfacing undated documents at the top. This is the red.
+        ArgumentCaptor<Pageable> captor = ArgumentCaptor.forClass(Pageable.class);
+        when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class)))
+                .thenReturn(new PageImpl<>(List.of()));
+
+        documentService.searchDocuments(null, null, null, null, null, null, null, null,
+                DocumentSort.DATE, "ASC", null, false, org.springframework.data.domain.PageRequest.of(0, 5));
+
+        verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), captor.capture());
+        Sort.Order dateOrder = captor.getValue().getSort().getOrderFor("documentDate");
+        assertThat(dateOrder).isNotNull();
+        assertThat(dateOrder.getDirection()).isEqualTo(Sort.Direction.ASC);
+        assertThat(dateOrder.getNullHandling()).isEqualTo(Sort.NullHandling.NULLS_LAST);
+    }
+
     @Test
     void searchDocuments_UPDATED_AT_sort_resolves_to_updatedAt_field() {
         ArgumentCaptor<Pageable> captor = ArgumentCaptor.forClass(Pageable.class);
@@ -1457,8 +1490,7 @@ class DocumentServiceTest {
                 .thenReturn(new PageImpl<>(List.of()));
 
         documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                DocumentSort.UPDATED_AT, "DESC", null,
-                org.springframework.data.domain.PageRequest.of(0, 5));
+                DocumentSort.UPDATED_AT, "DESC", null, false, org.springframework.data.domain.PageRequest.of(0, 5));
 
         verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), captor.capture());
         assertThat(captor.getValue().getSort())
@@ -1482,8 +1514,7 @@ class DocumentServiceTest {
                 .thenReturn(all);
 
         DocumentSearchResult result = documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                org.raddatz.familienarchiv.document.DocumentSort.SENDER, "asc", null,
-                org.springframework.data.domain.PageRequest.of(1, 50));
+                org.raddatz.familienarchiv.document.DocumentSort.SENDER, "asc", null, false, org.springframework.data.domain.PageRequest.of(1, 50));
 
         assertThat(result.totalElements()).isEqualTo(120L);
         assertThat(result.pageNumber()).isEqualTo(1);
@@ -1507,8 +1538,7 @@ class DocumentServiceTest {
                 .thenReturn(all);
 
         DocumentSearchResult result = documentService.searchDocuments(null, null, null, null, null, null, null, null,
-                org.raddatz.familienarchiv.document.DocumentSort.SENDER, "asc", null,
-                org.springframework.data.domain.PageRequest.of(10, 50));
+                org.raddatz.familienarchiv.document.DocumentSort.SENDER, "asc", null, false, org.springframework.data.domain.PageRequest.of(10, 50));
 
         assertThat(result.items()).isEmpty();
         assertThat(result.totalElements()).isEqualTo(30L);
@@ -1521,7 +1551,7 @@ class DocumentServiceTest {
         when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class)))
                 .thenReturn(new PageImpl<>(List.of()));
 
-        documentService.searchDocuments(null, null, null, null, null, null, null, DocumentStatus.REVIEWED, null, null, null, UNPAGED);
+        documentService.searchDocuments(null, null, null, null, null, null, null, DocumentStatus.REVIEWED, null, null, null, false, UNPAGED);
 
         verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class));
     }
@@ -1531,7 +1561,7 @@ class DocumentServiceTest {
         when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class)))
                 .thenReturn(new PageImpl<>(List.of()));
 
-        documentService.searchDocuments(null, null, null, null, null, null, null, null, null, null, null, UNPAGED);
+        documentService.searchDocuments(null, null, null, null, null, null, null, null, null, null, null, false, UNPAGED);
 
         verify(documentRepository).findAll(any(org.springframework.data.jpa.domain.Specification.class), any(Pageable.class));
     }
@@ -1609,7 +1639,7 @@ class DocumentServiceTest {
                 .thenReturn(List.of(withSender, noSender));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                null, null, null, null, null, null, null, null, DocumentSort.SENDER, "asc", null, UNPAGED);
+                null, null, null, null, null, null, null, null, DocumentSort.SENDER, "asc", null, false, UNPAGED);
 
         assertThat(result.items()).hasSize(2);
         assertThat(result.items()).extracting(DocumentListItem::title).containsExactly("Has Sender", "No Sender");
@@ -1629,12 +1659,53 @@ class DocumentServiceTest {
                 .thenReturn(List.of(noReceivers, withReceiver));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                null, null, null, null, null, null, null, null, DocumentSort.RECEIVER, "asc", null, UNPAGED);
+                null, null, null, null, null, null, null, null, DocumentSort.RECEIVER, "asc", null, false, UNPAGED);
 
         assertThat(result.items()).extracting(DocumentListItem::title)
                 .containsExactly("Has Receiver", "No Receivers");
     }
 
+    // ─── searchDocuments — undated docs stay in their person group (#668) ───────
+
+    @Test
+    void searchDocuments_senderSort_keepsUndatedDocumentUnderItsSender() {
+        // Locking test: the in-memory SENDER comparator orders by sender name, not
+        // date, so an undated (null documentDate) letter must NOT be pulled out of
+        // its sender's group — it sorts by sender exactly like a dated letter.
+        Person alice = Person.builder().id(UUID.randomUUID()).firstName("Alice").lastName("Ziegler").build();
+        Document datedFromAlice = Document.builder().id(UUID.randomUUID()).title("Dated")
+                .sender(alice).documentDate(LocalDate.of(1916, 6, 15)).build();
+        Document undatedFromAlice = Document.builder().id(UUID.randomUUID()).title("Undated")
+                .sender(alice).documentDate(null).build();
+
+        when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class)))
+                .thenReturn(List.of(datedFromAlice, undatedFromAlice));
+
+        DocumentSearchResult result = documentService.searchDocuments(
+                null, null, null, null, null, null, null, null, DocumentSort.SENDER, "asc", null, false, UNPAGED);
+
+        // Both stay together under Alice; neither is dropped or reordered by date.
+        assertThat(result.items()).extracting(DocumentListItem::title)
+                .containsExactlyInAnyOrder("Dated", "Undated");
+        assertThat(result.items()).allMatch(item -> item.sender().getId().equals(alice.getId()));
+    }
+
+    @Test
+    void searchDocuments_undatedTrue_usesSpecificationPath_notPureTextRelevanceShortcut() {
+        // undated=true must bypass the pure-text RELEVANCE SQL shortcut, which
+        // skips buildSearchSpec and would silently drop the undatedOnly predicate.
+        when(documentRepository.findAllMatchingIdsByFts("brief")).thenReturn(List.of(UUID.randomUUID()));
+        when(documentRepository.findAll(any(org.springframework.data.jpa.domain.Specification.class)))
+                .thenReturn(List.of());
+
+        documentService.searchDocuments("brief", null, null, null, null, null, null, null,
+                DocumentSort.RELEVANCE, null, null, true, UNPAGED);
+
+        // The FTS-id path (buildSearchSpec) ran; the raw-page SQL shortcut did not.
+        verify(documentRepository).findAllMatchingIdsByFts("brief");
+        verify(documentRepository, never()).findFtsPageRaw(anyString(), anyInt(), anyInt());
+    }
+
     @Test
     void searchDocuments_senderSort_nullLastNameSortsToEnd() {
         // Without fix: null lastName produces sort key "null Smith" which compares
@@ -1651,7 +1722,7 @@ class DocumentServiceTest {
                 .thenReturn(List.of(docNullName, docSmith));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                null, null, null, null, null, null, null, null, DocumentSort.SENDER, "asc", null, UNPAGED);
+                null, null, null, null, null, null, null, null, DocumentSort.SENDER, "asc", null, false, UNPAGED);
 
         // null lastName should sort to end (treated as empty), not before "smith" (as "null")
         assertThat(result.items()).extracting(DocumentListItem::title)
@@ -1674,7 +1745,7 @@ class DocumentServiceTest {
         when(documentRepository.findEnrichmentData(any(), eq("Brief"))).thenReturn(rows);
 
         DocumentSearchResult result = documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, UNPAGED);
+                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, false, UNPAGED);
 
         assertThat(result.items()).hasSize(1);
         SearchMatchData md = result.items().get(0).matchData();
@@ -1688,8 +1759,7 @@ class DocumentServiceTest {
                 .thenReturn(new PageImpl<>(List.of()));
 
         DocumentSearchResult result = documentService.searchDocuments(
-                null, null, null, null, null, null, null, null, null, null, null,
-                UNPAGED);
+                null, null, null, null, null, null, null, null, null, null, null, false, UNPAGED);
 
         assertThat(result.items()).isEmpty();
     }
@@ -1709,7 +1779,7 @@ class DocumentServiceTest {
         when(documentRepository.findEnrichmentData(any(), eq("Brief"))).thenReturn(rows);
 
         DocumentSearchResult result = documentService.searchDocuments(
-                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, UNPAGED);
+                "Brief", null, null, null, null, null, null, null, DocumentSort.RELEVANCE, null, null, false, UNPAGED);
 
         SearchMatchData md = result.items().get(0).matchData();
         assertThat(md.transcriptionSnippet()).isEqualTo("Hier ist der Brief aus Berlin");
@@ -2226,7 +2296,7 @@ class DocumentServiceTest {
                 .thenReturn(List.of(d1, d2));
 
         List<UUID> result = documentService.findIdsForFilter(
-                null, null, null, null, null, null, null, null, null);
+                null, null, null, null, null, null, null, null, null, false);
 
         assertThat(result).containsExactly(d1.getId(), d2.getId());
     }
@@ -2241,7 +2311,7 @@ class DocumentServiceTest {
         when(tagService.expandTagNamesToDescendantIdSets(any())).thenReturn(List.of());
 
         documentService.findIdsForFilter(
-                null, null, null, null, null, List.of("Brief"), null, null, TagOperator.OR);
+                null, null, null, null, null, List.of("Brief"), null, null, TagOperator.OR, false);
 
         // Spec built without throwing → OR branch was exercised. Coverage gain
         // is in not-throwing on the OR-specific code path; the actual SQL is
@@ -2254,7 +2324,7 @@ class DocumentServiceTest {
         when(documentRepository.findAllMatchingIdsByFts("xyz")).thenReturn(List.of());
 
         List<UUID> result = documentService.findIdsForFilter(
-                "xyz", null, null, null, null, null, null, null, null);
+                "xyz", null, null, null, null, null, null, null, null, false);
 
         assertThat(result).isEmpty();
         verify(documentRepository, never()).findAll(any(org.springframework.data.jpa.domain.Specification.class));

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

@@ -261,4 +261,21 @@ class DocumentSpecificationsTest {
         assertThat(result).isEmpty();
     }
 
+    // ─── undatedOnly ──────────────────────────────────────────────────────────
+
+    @Test
+    void undatedOnly_false_returnsAllDocuments() {
+        // false → no predicate (null), so the filter is a no-op (issue #668).
+        List<Document> result = documentRepository.findAll(Specification.where(undatedOnly(false)));
+        assertThat(result).hasSize(3);
+    }
+
+    @Test
+    void undatedOnly_true_returnsOnlyDocumentsWithoutADate() {
+        // Only the placeholder photo has a null documentDate in the fixture.
+        List<Document> result = documentRepository.findAll(Specification.where(undatedOnly(true)));
+        assertThat(result).extracting(Document::getTitle).containsExactly("Familienfoto");
+        assertThat(result).allMatch(d -> d.getDocumentDate() == null);
+    }
+
 }

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

@@ -0,0 +1,104 @@
+package org.raddatz.familienarchiv.document;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.config.FlywayConfig;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.data.jpa.test.autoconfigure.DataJpaTest;
+import org.springframework.boot.jdbc.test.autoconfigure.AutoConfigureTestDatabase;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.domain.Specification;
+
+import java.time.LocalDate;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.raddatz.familienarchiv.document.DocumentSpecifications.isBetween;
+import static org.raddatz.familienarchiv.document.DocumentSpecifications.undatedOnly;
+
+/**
+ * Real-Postgres assertions for issue #668. H2 disagrees with Postgres on
+ * {@code NULLS FIRST/LAST} defaults and on whether {@code BETWEEN} excludes
+ * NULL, so these guarantees MUST run against {@code postgres:16-alpine}, never
+ * an in-memory database.
+ */
+@DataJpaTest
+@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
+@Import({PostgresContainerConfig.class, FlywayConfig.class})
+class UndatedDocumentOrderingIntegrationTest {
+
+    @Autowired DocumentRepository documentRepository;
+
+    @BeforeEach
+    void setUp() {
+        documentRepository.deleteAll();
+        save("1916", LocalDate.of(1916, 6, 15));
+        save("1943", LocalDate.of(1943, 12, 24));
+        save("undated-a", null);
+        save("undated-b", null);
+    }
+
+    private void save(String title, LocalDate date) {
+        documentRepository.save(Document.builder()
+                .title(title)
+                .originalFilename(title + ".pdf")
+                .status(DocumentStatus.UPLOADED)
+                .metaDatePrecision(date == null ? DatePrecision.UNKNOWN : DatePrecision.DAY)
+                .documentDate(date)
+                .build());
+    }
+
+    @Test
+    void dateAscWithNullsLast_returnsDatedFirstUndatedLast() {
+        Sort sort = Sort.by(new Sort.Order(Sort.Direction.ASC, "documentDate").nullsLast());
+
+        List<Document> result = documentRepository.findAll(sort);
+
+        assertThat(result).hasSize(4);
+        assertThat(result.get(0).getDocumentDate()).isEqualTo(LocalDate.of(1916, 6, 15));
+        assertThat(result.get(1).getDocumentDate()).isEqualTo(LocalDate.of(1943, 12, 24));
+        assertThat(result.get(2).getDocumentDate()).isNull();
+        assertThat(result.get(3).getDocumentDate()).isNull();
+    }
+
+    @Test
+    void undatedOnly_returnsExactlyTheNullDatedRows() {
+        List<Document> result = documentRepository.findAll(undatedOnly(true));
+
+        assertThat(result).hasSize(2);
+        assertThat(result).allMatch(d -> d.getDocumentDate() == null);
+    }
+
+    @Test
+    void undatedOnly_false_returnsAllRows() {
+        Specification<Document> spec = Specification.where(undatedOnly(false));
+
+        List<Document> result = documentRepository.findAll(spec);
+
+        assertThat(result).hasSize(4);
+    }
+
+    @Test
+    void dateRange_excludesUndatedRows() {
+        List<Document> result = documentRepository.findAll(isBetween(
+                LocalDate.of(1900, 1, 1), LocalDate.of(2000, 12, 31)));
+
+        assertThat(result).hasSize(2);
+        assertThat(result).allMatch(d -> d.getDocumentDate() != null);
+    }
+
+    @Test
+    void undatedOnly_combinedWithDateRange_returnsEmpty() {
+        // The collision rule (#668): a from/to range and undated=true are mutually
+        // exclusive — a row cannot both have a null date and fall inside a range.
+        Specification<Document> spec = Specification
+                .where(undatedOnly(true))
+                .and(isBetween(LocalDate.of(1900, 1, 1), LocalDate.of(2000, 12, 31)));
+
+        List<Document> result = documentRepository.findAll(spec);
+
+        assertThat(result).isEmpty();
+    }
+}

frontend/messages/de.json

@@ -100,6 +100,8 @@
 	"docs_list_summary": "Zusammenfassung",
 	"docs_list_unknown": "Unbekannt",
 	"docs_group_undated": "Undatiert",
+	"docs_filter_undated_only": "Nur undatierte",
+	"docs_range_excludes_undated": "Ein Datumsfilter schließt undatierte Dokumente aus, da sie keinem Zeitraum zugeordnet werden können.",
 	"docs_group_unknown": "Unbekannt",
 	"doc_section_who_when": "Wer & Wann",
 	"doc_section_description": "Beschreibung",

frontend/messages/en.json

@@ -100,6 +100,8 @@
 	"docs_list_summary": "Summary",
 	"docs_list_unknown": "Unknown",
 	"docs_group_undated": "Undated",
+	"docs_filter_undated_only": "Undated only",
+	"docs_range_excludes_undated": "A date range filter excludes undated documents, because they cannot belong to any time span.",
 	"docs_group_unknown": "Unknown",
 	"doc_section_who_when": "Who & When",
 	"doc_section_description": "Description",

frontend/messages/es.json

@@ -100,6 +100,8 @@
 	"docs_list_summary": "Resumen",
 	"docs_list_unknown": "Desconocido",
 	"docs_group_undated": "Sin fecha",
+	"docs_filter_undated_only": "Solo sin fecha",
+	"docs_range_excludes_undated": "Un filtro de intervalo de fechas excluye los documentos sin fecha, ya que no pueden pertenecer a ningún periodo.",
 	"docs_group_unknown": "Desconocido",
 	"doc_section_who_when": "Quién & Cuándo",
 	"doc_section_description": "Descripción",

frontend/src/lib/activity/ChronikRow.svelte.spec.ts

@@ -44,6 +44,17 @@ describe('ChronikRow', () => {
 		expect(link).not.toBeNull();
 	});
 
+	// --- #668 negative guarantee: Chronik never fabricates a letter date ---
+	it('renders the activity timestamp, not a letter date, and no undated badge', async () => {
+		// The row shows the relative activity time (happenedAt), never the letter's
+		// documentDate — ActivityFeedItemDTO carries no date surface to badge.
+		render(ChronikRow, { item: baseItem });
+		// No undated badge is introduced into a Chronik row.
+		expect(document.querySelector('[data-testid="undated-badge"]')).toBeNull();
+		// No fabricated "Datum unbekannt" letter-date label appears.
+		await expect.element(page.getByText('Datum unbekannt')).not.toBeInTheDocument();
+	});
+
 	// --- simple variant ---
 	it('renders simple variant when count === 1 and not a mention', async () => {
 		render(ChronikRow, { item: baseItem });

frontend/src/lib/document/DocumentDate.svelte

@@ -28,13 +28,21 @@ const showRawLine = $derived(
 </script>
 
 <span class="inline-flex flex-col">
-	<span class="inline-flex items-center gap-1">
-		{#if isUnknown}
-			<!-- Non-color cue (WCAG 1.4.1): a calendar-with-question glyph. The visible
-			     "Datum unbekannt" text is the redundant textual cue, so the icon is
-			     decorative and hidden from assistive tech (per Leonie's a11y note). -->
+	{#if isUnknown}
+		<!--
+			Neutral metadata chip (#668): an undated letter is an absence, NOT an error,
+			so the chip is neutral (text-ink-3 on bg-surface, ≥4.5:1 in both themes) —
+			never red/amber. Matches the archive-metadata chip pattern in the row. The
+			non-color cue (WCAG 1.4.1) is the calendar-with-question glyph; the visible
+			"Datum unbekannt" text is the redundant textual cue and IS the accessibility,
+			so it is announced inline (never aria-hidden) while the icon is decorative.
+		-->
+		<span
+			data-testid="undated-badge"
+			class="inline-flex items-center gap-1 rounded border border-line px-1.5 py-0.5 font-sans text-[10px] tracking-widest text-ink-3 uppercase"
+		>
 			<svg
-				class="h-3.5 w-3.5 shrink-0 text-ink-3"
+				class="h-3 w-3 shrink-0 text-ink-3"
 				viewBox="0 0 24 24"
 				fill="none"
 				stroke="currentColor"
@@ -48,9 +56,13 @@ const showRawLine = $derived(
 				<path d="M9 16a1.5 1.5 0 0 1 3 0c0 1-1.5 1.2-1.5 2.2" />
 				<path d="M10.5 21h.01" />
 			</svg>
-		{/if}
-		<span>{label}</span>
-	</span>
+			{label}
+		</span>
+	{:else}
+		<span class="inline-flex items-center gap-1">
+			<span>{label}</span>
+		</span>
+	{/if}
 	{#if showRawLine}
 		<!-- Visible secondary line (WCAG 1.4.13 — not tooltip-only). raw is untrusted
 		     verbatim spreadsheet text; rendered via default Svelte interpolation, which

frontend/src/lib/document/DocumentRow.svelte

@@ -168,16 +168,12 @@ function safeTagColor(color: string | null | undefined): string {
 						     document DETAIL page, never in list/search rows — list rows surface only the
 						     honest label to keep scan-rows compact. showRaw={false} enforces this; the
 						     DocumentListItem payload also intentionally omits metaDateRaw. -->
-						{#if doc.documentDate}
-							<DocumentDate
-								iso={doc.documentDate}
-								precision={doc.metaDatePrecision}
-								end={doc.metaDateEnd}
-								showRaw={false}
-							/>
-						{:else}
-							—
-						{/if}
+						<DocumentDate
+							iso={doc.documentDate}
+							precision={doc.metaDatePrecision}
+							end={doc.metaDateEnd}
+							showRaw={false}
+						/>
 					</div>
 					<div class="flex items-start gap-2">
 						<ProgressRing percentage={item.completionPercentage} />

frontend/src/lib/document/DocumentRow.svelte.spec.ts

@@ -73,6 +73,35 @@ describe('DocumentRow – title', () => {
 	});
 });
 
+// ─── Date rendering (#668) ──────────────────────────────────────────────────
+
+describe('DocumentRow – date rendering', () => {
+	it('renders a "Datum unbekannt" badge for an undated document', async () => {
+		const item = makeItem({ documentDate: undefined, metaDatePrecision: 'UNKNOWN' });
+		render(DocumentRow, { item });
+		// The badge text appears (once per breakpoint block).
+		await expect.element(page.getByText('Datum unbekannt').first()).toBeInTheDocument();
+	});
+
+	it('does not render a bare em-dash for an undated document', async () => {
+		const item = makeItem({ documentDate: undefined, metaDatePrecision: 'UNKNOWN' });
+		render(DocumentRow, { item });
+		await expect.element(page.getByText('—', { exact: true }).first()).not.toBeInTheDocument();
+	});
+
+	it('renders the full date for a day-precision document', async () => {
+		const item = makeItem({ documentDate: '1943-12-24', metaDatePrecision: 'DAY' });
+		render(DocumentRow, { item });
+		await expect.element(page.getByText(/24\. Dezember 1943/).first()).toBeInTheDocument();
+	});
+
+	it('renders month precision honestly without fabricating a day', async () => {
+		const item = makeItem({ documentDate: '1916-06-01', metaDatePrecision: 'MONTH' });
+		render(DocumentRow, { item });
+		await expect.element(page.getByText(/Juni 1916/).first()).toBeInTheDocument();
+	});
+});
+
 // ─── Snippet ──────────────────────────────────────────────────────────────────
 
 describe('DocumentRow – snippet', () => {

frontend/src/lib/generated/api.ts

@@ -5083,6 +5083,8 @@ export interface operations {
                 dir?: string;
                 /** @description Tag operator: AND (default) or OR */
                 tagOp?: string;
+                /** @description Restrict to undated documents (meta_date IS NULL) */
+                undated?: boolean;
                 /** @description Page number (0-indexed) */
                 page?: number;
                 /** @description Page size (max 100) */
@@ -5184,6 +5186,7 @@ export interface operations {
                 tagQ?: string;
                 status?: "PLACEHOLDER" | "UPLOADED" | "TRANSCRIBED" | "REVIEWED" | "ARCHIVED";
                 tagOp?: string;
+                undated?: boolean;
             };
             header?: never;
             path?: never;

frontend/src/routes/DocumentList.svelte

@@ -15,7 +15,9 @@ let {
 	error,
 	total = 0,
 	q = '',
-	sort = 'DATE'
+	sort = 'DATE',
+	from = '',
+	to = ''
 }: {
 	items: DocumentListItem[];
 	canWrite: boolean;
@@ -23,8 +25,15 @@ let {
 	total?: number;
 	q?: string;
 	sort?: SortMode;
+	from?: string;
+	to?: string;
 } = $props();
 
+// A from/to range excludes undated documents — when it yields nothing, the
+// empty state must say so explicitly (a localized constant, never a reflected
+// backend string). Issue #668.
+const hasDateRange = $derived(!!from || !!to);
+
 const groups = $derived.by(() => {
 	if (sort === 'SENDER') return groupBySender(items);
 	if (sort === 'RECEIVER') return groupByReceiver(items);
@@ -119,7 +128,13 @@ function groupByReceiver(docItems: DocumentListItem[]) {
 			</div>
 			<h3 class="font-serif text-lg font-medium text-ink">{m.docs_empty_heading()}</h3>
 			<p class="mt-1 font-sans text-sm text-ink-2">
-				{q ? m.docs_empty_for_term({ term: q }) : m.docs_empty_text()}
+				{#if hasDateRange}
+					{m.docs_range_excludes_undated()}
+				{:else if q}
+					{m.docs_empty_for_term({ term: q })}
+				{:else}
+					{m.docs_empty_text()}
+				{/if}
 			</p>
 			<button
 				onclick={() => goto('/documents')}

frontend/src/routes/DocumentList.svelte.spec.ts

@@ -16,6 +16,7 @@ function makeItem(overrides: Partial<DocumentListItem> = {}): DocumentListItem {
 		title: 'Testbrief',
 		originalFilename: 'testbrief.pdf',
 		documentDate: '2024-03-15',
+		metaDatePrecision: 'DAY',
 		sender: undefined,
 		receivers: [],
 		tags: [],
@@ -278,3 +279,85 @@ describe('DocumentList – DocumentRow delegation', () => {
 		await expect.element(mark).toHaveTextContent('Brief');
 	});
 });
+
+// ─── Undated badge in person-grouped modes (#668) ────────────────────────────
+
+describe('DocumentList – undated badge in person grouping', () => {
+	const sender = {
+		id: 's1',
+		lastName: 'Mustermann',
+		displayName: 'Max Mustermann',
+		personType: 'PERSON' as const,
+		familyMember: false,
+		provisional: false
+	};
+	const receiver = {
+		id: 'r1',
+		lastName: 'Brandt',
+		displayName: 'Felix Brandt',
+		personType: 'PERSON' as const,
+		familyMember: false,
+		provisional: false
+	};
+
+	it('shows the undated badge on a row under SENDER grouping', async () => {
+		const items = [
+			makeItem({ id: '1', documentDate: undefined, metaDatePrecision: 'UNKNOWN', sender })
+		];
+		render(DocumentList, { ...baseProps, items, total: 1, sort: 'SENDER' });
+		await expect.element(page.getByTestId('undated-badge').first()).toBeInTheDocument();
+	});
+
+	it('shows the undated badge on a row under RECEIVER grouping', async () => {
+		const items = [
+			makeItem({
+				id: '1',
+				documentDate: undefined,
+				metaDatePrecision: 'UNKNOWN',
+				receivers: [receiver]
+			})
+		];
+		render(DocumentList, { ...baseProps, items, total: 1, sort: 'RECEIVER' });
+		await expect.element(page.getByTestId('undated-badge').first()).toBeInTheDocument();
+	});
+
+	it('keeps an undated letter under its sender, not in a synthetic undated sub-group', async () => {
+		const items = [
+			makeItem({ id: '1', documentDate: '1916-06-15', metaDatePrecision: 'DAY', sender }),
+			makeItem({ id: '2', documentDate: undefined, metaDatePrecision: 'UNKNOWN', sender })
+		];
+		render(DocumentList, { ...baseProps, items, total: 2, sort: 'SENDER' });
+		// One sender card; no "Undatiert" group header inside person-grouped mode.
+		await expect
+			.element(page.getByTestId('group-header').filter({ hasText: 'Max Mustermann' }))
+			.toBeInTheDocument();
+		await expect.element(page.getByText('Undatiert')).not.toBeInTheDocument();
+		const cards = page.getByTestId('group-card');
+		await expect.element(cards.nth(1)).not.toBeInTheDocument();
+	});
+});
+
+// ─── Date-range / undated empty state (#668) ─────────────────────────────────
+
+describe('DocumentList – range-excludes-undated empty state', () => {
+	it('explains that a date range excludes undated documents when from/to active and no results', async () => {
+		render(DocumentList, {
+			...baseProps,
+			items: [],
+			total: 0,
+			from: '1920-01-01',
+			to: '1930-12-31'
+		});
+		await expect
+			.element(page.getByText(/Datumsfilter schließt undatierte Dokumente aus/))
+			.toBeInTheDocument();
+	});
+
+	it('shows the generic empty state when no date range is active', async () => {
+		render(DocumentList, { ...baseProps, items: [], total: 0 });
+		await expect.element(page.getByText(/Keine Dokumente/)).toBeInTheDocument();
+		await expect
+			.element(page.getByText(/Datumsfilter schließt undatierte Dokumente aus/))
+			.not.toBeInTheDocument();
+	});
+});

frontend/src/routes/SearchFilterBar.svelte

@@ -15,6 +15,7 @@ let {
 	tagNames = $bindable<{ name: string; id?: string; color?: string; parentId?: string }[]>([]),
 	tagQ = $bindable(''),
 	tagOperator = $bindable<'AND' | 'OR'>('AND'),
+	undated = $bindable(false),
 	sort = $bindable('DATE'),
 	dir = $bindable('desc'),
 	showAdvanced = $bindable(false),
@@ -35,6 +36,7 @@ let {
 	tagNames?: { name: string; id?: string; color?: string; parentId?: string }[];
 	tagQ?: string;
 	tagOperator?: 'AND' | 'OR';
+	undated?: boolean;
 	sort?: string;
 	dir?: string;
 	showAdvanced?: boolean;
@@ -248,6 +250,33 @@ $effect(() => {
 					/>
 				</div>
 			</div>
+
+			<!-- Undated-only triage toggle (#668). aria-pressed states the toggle, not a
+			     colour; min-h-[44px] meets the senior-audience touch target (WCAG 2.5.5). -->
+			<div class="md:col-span-12">
+				<button
+					type="button"
+					data-testid="undated-only-toggle"
+					aria-pressed={undated}
+					onclick={() => {
+						undated = !undated;
+						(onSearchImmediate ?? onSearch)();
+					}}
+					class="inline-flex min-h-[44px] items-center gap-2 rounded border px-3 text-xs font-bold tracking-widest uppercase transition-colors {undated
+						? 'border-primary bg-primary text-primary-fg'
+						: 'border-line bg-muted text-ink-2 hover:bg-line'}"
+				>
+					<span
+						aria-hidden="true"
+						class="inline-flex h-4 w-4 items-center justify-center rounded-sm border {undated
+							? 'border-primary-fg bg-primary-fg/20'
+							: 'border-ink-3'}"
+					>
+						{#if undated}✓{/if}
+					</span>
+					{m.docs_filter_undated_only()}
+				</button>
+			</div>
 		</div>
 	{/if}
 </div>

frontend/src/routes/SearchFilterBar.svelte.spec.ts

@@ -128,6 +128,42 @@ describe('SearchFilterBar – AND/OR tag operator toggle', () => {
 	});
 });
 
+describe('SearchFilterBar – undated-only toggle (#668)', () => {
+	async function openAdvanced() {
+		const filterBtn = page.getByRole('button', { name: 'Filter', exact: true });
+		await filterBtn.click();
+	}
+
+	it('renders the "Nur undatierte" toggle in the advanced row', async () => {
+		render(SearchFilterBar, { ...defaultProps, sort: 'DATE', dir: 'desc' });
+		await openAdvanced();
+		await expect.element(page.getByTestId('undated-only-toggle')).toBeInTheDocument();
+	});
+
+	it('reflects the active undated state via aria-pressed', async () => {
+		render(SearchFilterBar, { ...defaultProps, sort: 'DATE', dir: 'desc', undated: true });
+		await openAdvanced();
+		await expect
+			.element(page.getByTestId('undated-only-toggle'))
+			.toHaveAttribute('aria-pressed', 'true');
+	});
+
+	it('calls onSearchImmediate when the undated toggle is clicked', async () => {
+		const onSearch = vi.fn();
+		const onSearchImmediate = vi.fn();
+		render(SearchFilterBar, {
+			...defaultProps,
+			onSearch,
+			onSearchImmediate,
+			sort: 'DATE',
+			dir: 'desc'
+		});
+		await openAdvanced();
+		await page.getByTestId('undated-only-toggle').click();
+		await expect.poll(() => onSearchImmediate.mock.calls.length).toBeGreaterThan(0);
+	});
+});
+
 describe('SearchFilterBar – tagQ live filter', () => {
 	it('calls onSearch when tag text changes in TagInput', async () => {
 		vi.stubGlobal(

frontend/src/routes/documents/+page.server.ts

@@ -46,6 +46,8 @@ export async function load({ url, fetch }) {
 		: 'desc';
 	const tagQ = url.searchParams.get('tagQ') || '';
 	const tagOp = url.searchParams.get('tagOp') === 'OR' ? 'OR' : 'AND';
+	// Narrow the accepted truthy surface to exactly "true" (mirrors the tagOp clamp).
+	const undated = url.searchParams.get('undated') === 'true';
 	const page = Math.max(0, Number(url.searchParams.get('page') ?? '0') || 0);
 
 	const api = createApiClient(fetch);
@@ -66,6 +68,7 @@ export async function load({ url, fetch }) {
 						tag: tags.length ? tags : undefined,
 						tagQ: tagQ && !tags.length ? tagQ : undefined,
 						tagOp: tagOp === 'OR' ? 'OR' : undefined,
+						undated: undated || undefined,
 						sort,
 						dir: dir || undefined,
 						page,
@@ -94,6 +97,7 @@ export async function load({ url, fetch }) {
 			dir,
 			tagQ,
 			tagOp,
+			undated,
 			error: 'Daten konnten nicht geladen werden.' as string | null
 		};
 	}
@@ -124,6 +128,7 @@ export async function load({ url, fetch }) {
 		dir,
 		tagQ,
 		tagOp,
+		undated,
 		error: errorMessage
 	};
 }

frontend/src/routes/documents/+page.svelte

@@ -32,10 +32,16 @@ let sort = $state(untrack(() => data.sort || 'DATE'));
 let dir = $state(untrack(() => data.dir || 'desc'));
 let tagQ = $state(untrack(() => data.tagQ || ''));
 let tagOperator = $state<'AND' | 'OR'>(untrack(() => (data.tagOp as 'AND' | 'OR') || 'AND'));
+let undated = $state(untrack(() => data.undated ?? false));
 
 function hasAdvancedFilters() {
 	return (
-		(data.tags?.length ?? 0) > 0 || !!data.senderId || !!data.receiverId || !!data.from || !!data.to
+		(data.tags?.length ?? 0) > 0 ||
+		!!data.senderId ||
+		!!data.receiverId ||
+		!!data.from ||
+		!!data.to ||
+		!!data.undated
 	);
 }
 
@@ -54,6 +60,7 @@ type FilterSnapshot = {
 	dir: string;
 	tagQ: string;
 	tagOp: 'AND' | 'OR';
+	undated: boolean;
 	zoomFrom?: string | null;
 	zoomTo?: string | null;
 };
@@ -77,6 +84,7 @@ function buildSearchParams(filters: FilterSnapshot, targetPage?: number): Svelte
 	if (filters.dir) params.set('dir', filters.dir);
 	if (filters.tagQ) params.set('tagQ', filters.tagQ);
 	if (filters.tagOp === 'OR') params.set('tagOp', 'OR');
+	if (filters.undated) params.set('undated', 'true');
 	if (filters.zoomFrom) params.set('zoomFrom', filters.zoomFrom);
 	if (filters.zoomTo) params.set('zoomTo', filters.zoomTo);
 	if (targetPage !== undefined && targetPage > 0) params.set('page', String(targetPage));
@@ -112,6 +120,7 @@ function navigateWithZoom(zoomFrom: string | null, zoomTo: string | null) {
 		dir,
 		tagQ,
 		tagOp: tagOperator,
+		undated,
 		zoomFrom,
 		zoomTo
 	});
@@ -136,7 +145,8 @@ function buildPageHref(targetPage: number): string {
 			sort: data.sort || '',
 			dir: data.dir || '',
 			tagQ: data.tagQ || '',
-			tagOp: (data.tagOp as 'AND' | 'OR') || 'AND'
+			tagOp: (data.tagOp as 'AND' | 'OR') || 'AND',
+			undated: data.undated ?? false
 		},
 		targetPage
 	);
@@ -188,7 +198,8 @@ async function editAllMatching() {
 			sort: '',
 			dir: '',
 			tagQ: data.tagQ || '',
-			tagOp: (data.tagOp as 'AND' | 'OR') || 'AND'
+			tagOp: (data.tagOp as 'AND' | 'OR') || 'AND',
+			undated: data.undated ?? false
 		});
 		params.delete('sort');
 		params.delete('dir');
@@ -226,6 +237,7 @@ $effect(() => {
 	dir = data.dir || 'desc';
 	tagQ = data.tagQ || '';
 	tagOperator = (data.tagOp as 'AND' | 'OR') || 'AND';
+	undated = data.undated ?? false;
 	if (hasAdvancedFilters()) showAdvanced = true;
 });
 </script>
@@ -255,6 +267,7 @@ $effect(() => {
 		bind:dir={dir}
 		bind:tagQ={tagQ}
 		bind:tagOperator={tagOperator}
+		bind:undated={undated}
 		initialSenderName={initialSenderName}
 		initialReceiverName={initialReceiverName}
 		navKey={navKey}
@@ -343,6 +356,8 @@ $effect(() => {
 		canWrite={data.canWrite}
 		error={data.error}
 		sort={sort}
+		from={data.from}
+		to={data.to}
 	/>
 
 	<Pagination page={data.pageNumber} totalPages={data.totalPages} makeHref={buildPageHref} />

frontend/src/routes/documents/page.server.spec.ts

@@ -100,6 +100,106 @@ describe('documents page load — search params', () => {
 		);
 	});
 
+	it('forwards undated=true to the search API as a boolean true', async () => {
+		const mockGet = vi.fn().mockResolvedValue({
+			response: { ok: true, status: 200 },
+			data: { items: [], totalElements: 0, pageNumber: 0, pageSize: 50, totalPages: 0 }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ GET: mockGet } as ReturnType<
+			typeof createApiClient
+		>);
+
+		await load({
+			url: makeUrl({ undated: 'true' }),
+			request: new Request('http://localhost/documents'),
+			fetch: vi.fn() as unknown as typeof fetch
+		});
+
+		expect(mockGet).toHaveBeenCalledWith(
+			'/api/documents/search',
+			expect.objectContaining({
+				params: expect.objectContaining({
+					query: expect.objectContaining({ undated: true })
+				})
+			})
+		);
+	});
+
+	it('omits undated from the query when the param is absent', async () => {
+		const mockGet = vi.fn().mockResolvedValue({
+			response: { ok: true, status: 200 },
+			data: { items: [], totalElements: 0, pageNumber: 0, pageSize: 50, totalPages: 0 }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ GET: mockGet } as ReturnType<
+			typeof createApiClient
+		>);
+
+		await load({
+			url: makeUrl({}),
+			request: new Request('http://localhost/documents'),
+			fetch: vi.fn() as unknown as typeof fetch
+		});
+
+		const query = mockGet.mock.calls[0][1].params.query;
+		expect(query.undated).toBeUndefined();
+	});
+
+	it('treats any undated value other than the literal "true" as not-undated', async () => {
+		const mockGet = vi.fn().mockResolvedValue({
+			response: { ok: true, status: 200 },
+			data: { items: [], totalElements: 0, pageNumber: 0, pageSize: 50, totalPages: 0 }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ GET: mockGet } as ReturnType<
+			typeof createApiClient
+		>);
+
+		const result = await load({
+			url: makeUrl({ undated: '1' }),
+			request: new Request('http://localhost/documents'),
+			fetch: vi.fn() as unknown as typeof fetch
+		});
+
+		expect(result.undated).toBe(false);
+		expect(mockGet.mock.calls[0][1].params.query.undated).toBeUndefined();
+	});
+
+	it('returns the undated flag in page data when enabled', async () => {
+		const mockGet = vi.fn().mockResolvedValue({
+			response: { ok: true, status: 200 },
+			data: { items: [], totalElements: 0, pageNumber: 0, pageSize: 50, totalPages: 0 }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ GET: mockGet } as ReturnType<
+			typeof createApiClient
+		>);
+
+		const result = await load({
+			url: makeUrl({ undated: 'true' }),
+			request: new Request('http://localhost/documents'),
+			fetch: vi.fn() as unknown as typeof fetch
+		});
+
+		expect(result.undated).toBe(true);
+	});
+
+	it('does not carry page when toggling undated (page reset)', async () => {
+		const mockGet = vi.fn().mockResolvedValue({
+			response: { ok: true, status: 200 },
+			data: { items: [], totalElements: 0, pageNumber: 0, pageSize: 50, totalPages: 0 }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ GET: mockGet } as ReturnType<
+			typeof createApiClient
+		>);
+
+		// A bare undated toggle URL carries no page param → loader requests page 0.
+		await load({
+			url: makeUrl({ undated: 'true' }),
+			request: new Request('http://localhost/documents'),
+			fetch: vi.fn() as unknown as typeof fetch
+		});
+
+		expect(mockGet.mock.calls[0][1].params.query.page).toBe(0);
+	});
+
 	it('returns items and total from the search result', async () => {
 		const item = {
 			document: { id: 'd1' },