fix(review): address reviewer concerns from PR #661

- Replace brittle createdAt===updatedAt isNew() check with a 7-day
  recency window (created within last 7 days = new)
- Add createdAt/updatedAt to searchItem fixture in page.server.spec.ts
  and assert they are propagated to recentDocs
- Replace null timestamps in DocumentListItem test fixtures with a fixed
  LocalDateTime to satisfy the @Schema(required) contract

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

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

@@ -135,7 +135,8 @@ class DocumentControllerTest {
                 .thenReturn(DocumentSearchResult.of(List.of(new DocumentListItem(
                         docId, "Brief an Anna", "brief.pdf", null, null, null,
                         List.of(), List.of(), null, null, null, null,
-                        0, List.of(), matchData, null, null))));
+                        0, List.of(), matchData,
+                        LocalDateTime.of(2026, 1, 15, 10, 0), LocalDateTime.of(2026, 1, 15, 10, 0)))));
 
         mockMvc.perform(get("/api/documents/search").param("q", "Brief"))
                 .andExpect(status().isOk())
@@ -153,7 +154,8 @@ class DocumentControllerTest {
                 .thenReturn(DocumentSearchResult.of(List.of(new DocumentListItem(
                         docId, "Brief an Anna", "brief.pdf", null, null, null,
                         List.of(), List.of(), null, null, null, null,
-                        0, List.of(), matchData, null, null))));
+                        0, List.of(), matchData,
+                        LocalDateTime.of(2026, 1, 15, 10, 0), LocalDateTime.of(2026, 1, 15, 10, 0)))));
 
         mockMvc.perform(get("/api/documents/search"))
                 .andExpect(status().isOk())

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

@@ -5,6 +5,7 @@ import org.junit.jupiter.api.Test;
 import org.raddatz.familienarchiv.audit.ActivityActorDTO;
 import org.springframework.data.domain.PageRequest;
 
+import java.time.LocalDateTime;
 import java.util.List;
 import java.util.UUID;
 
@@ -16,7 +17,8 @@ class DocumentSearchResultTest {
         return new DocumentListItem(
                 docId, "Test", "test.pdf", null, null, null,
                 List.of(), List.of(), null, null, null, null,
-                0, List.of(), SearchMatchData.empty(), null, null);
+                0, List.of(), SearchMatchData.empty(),
+                LocalDateTime.of(2026, 1, 15, 10, 0), LocalDateTime.of(2026, 1, 15, 10, 0));
     }
 
     @Test
@@ -66,7 +68,8 @@ class DocumentSearchResultTest {
         DocumentListItem item = new DocumentListItem(
                 id, "T", "t.pdf", null, null, null,
                 List.of(), List.of(), null, null, null, null,
-                75, List.of(actor), SearchMatchData.empty(), null, null);
+                75, List.of(actor), SearchMatchData.empty(),
+                LocalDateTime.of(2026, 1, 15, 10, 0), LocalDateTime.of(2026, 1, 15, 10, 0));
 
         DocumentSearchResult result = DocumentSearchResult.of(List.of(item));