feat(bulk-edit): add PATCH /api/documents/bulk endpoint

WRITE_ALL-gated batch endpoint that applies a partial DTO to up to 500
documents per request. Per-document failures (DOCUMENT_NOT_FOUND, etc.)
are collected into the response's errors[] without aborting the batch.
Logs an audit line consistent with quickUpload.

Refs #225

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

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

@@ -18,7 +18,10 @@ import jakarta.validation.constraints.Min;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.validation.annotation.Validated;
+import org.raddatz.familienarchiv.dto.BulkEditError;
+import org.raddatz.familienarchiv.dto.BulkEditResult;
 import org.raddatz.familienarchiv.dto.DocumentBatchMetadataDTO;
+import org.raddatz.familienarchiv.dto.DocumentBulkEditDTO;
 import org.raddatz.familienarchiv.dto.DocumentSearchResult;
 import org.raddatz.familienarchiv.dto.DocumentUpdateDTO;
 import org.raddatz.familienarchiv.dto.TagOperator;
@@ -237,6 +240,45 @@ public class DocumentController {
         return new QuickUploadResult(created, updated, errors);
     }
 
+    // --- BULK EDIT ---
+
+    private static final int BULK_EDIT_MAX_IDS = 500;
+
+    @PatchMapping("/bulk")
+    @RequirePermission(Permission.WRITE_ALL)
+    public BulkEditResult patchBulk(
+            @RequestBody DocumentBulkEditDTO dto,
+            Authentication authentication) {
+        if (dto.getDocumentIds() == null || dto.getDocumentIds().isEmpty()) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "documentIds is required");
+        }
+        if (dto.getDocumentIds().size() > BULK_EDIT_MAX_IDS) {
+            throw DomainException.badRequest(ErrorCode.BULK_EDIT_TOO_MANY_IDS,
+                    "Maximum " + BULK_EDIT_MAX_IDS + " documents per request, got: " + dto.getDocumentIds().size());
+        }
+
+        UUID actorId = requireUserId(authentication);
+        int updated = 0;
+        List<BulkEditError> errors = new ArrayList<>();
+
+        for (UUID id : dto.getDocumentIds()) {
+            try {
+                documentService.applyBulkEditToDocument(id, dto);
+                updated++;
+            } catch (DomainException e) {
+                errors.add(new BulkEditError(id, e.getMessage()));
+            } catch (Exception e) {
+                errors.add(new BulkEditError(id, "Internal error"));
+                log.warn("Bulk edit failed for document {}: {}", id, e.getMessage());
+            }
+        }
+
+        log.info("bulkEdit actor={} documentIds={} updated={} errors={}",
+                actorId, dto.getDocumentIds().size(), updated, errors.size());
+
+        return new BulkEditResult(updated, errors);
+    }
+
     @GetMapping("/incomplete-count")
     @RequirePermission(Permission.WRITE_ALL)
     public Map<String, Long> getIncompleteCount() {

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

@@ -929,4 +929,112 @@ class DocumentControllerTest {
                 .andExpect(status().isBadRequest())
                 .andExpect(jsonPath("$.code").value("BATCH_TOO_LARGE"));
     }
+
+    // ─── PATCH /api/documents/bulk ───────────────────────────────────────────
+
+    private static String bulkBody(String... uuids) {
+        StringBuilder sb = new StringBuilder("{\"documentIds\":[");
+        for (int i = 0; i < uuids.length; i++) {
+            if (i > 0) sb.append(",");
+            sb.append("\"").append(uuids[i]).append("\"");
+        }
+        sb.append("]}");
+        return sb.toString();
+    }
+
+    @Test
+    void patchBulk_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(bulkBody(UUID.randomUUID().toString())))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser
+    void patchBulk_returns403_forReadAllUser() throws Exception {
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(bulkBody(UUID.randomUUID().toString())))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void patchBulk_returns400_whenDocumentIdsIsEmpty() throws Exception {
+        when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
+
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"documentIds\":[]}"))
+                .andExpect(status().isBadRequest());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void patchBulk_returns400_whenDocumentIdsIsMissing() throws Exception {
+        when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
+
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{}"))
+                .andExpect(status().isBadRequest());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void patchBulk_returns400_whenDocumentIdsExceedsCap() throws Exception {
+        when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
+
+        String[] ids = new String[501];
+        for (int i = 0; i < 501; i++) ids[i] = UUID.randomUUID().toString();
+
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(bulkBody(ids)))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("BULK_EDIT_TOO_MANY_IDS"));
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void patchBulk_returns200_andCallsServiceForEachId() throws Exception {
+        when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
+        UUID id1 = UUID.randomUUID();
+        UUID id2 = UUID.randomUUID();
+        when(documentService.applyBulkEditToDocument(any(), any()))
+                .thenAnswer(inv -> Document.builder().id(inv.getArgument(0)).build());
+
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(bulkBody(id1.toString(), id2.toString())))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.updated").value(2))
+                .andExpect(jsonPath("$.errors").isEmpty());
+
+        verify(documentService).applyBulkEditToDocument(eq(id1), any());
+        verify(documentService).applyBulkEditToDocument(eq(id2), any());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void patchBulk_returnsPartialFailureShape_whenServiceThrowsForOneDocument() throws Exception {
+        when(userService.findByEmail(any())).thenReturn(AppUser.builder().id(UUID.randomUUID()).build());
+        UUID okId = UUID.randomUUID();
+        UUID badId = UUID.randomUUID();
+        when(documentService.applyBulkEditToDocument(eq(okId), any()))
+                .thenAnswer(inv -> Document.builder().id(okId).build());
+        when(documentService.applyBulkEditToDocument(eq(badId), any()))
+                .thenThrow(org.raddatz.familienarchiv.exception.DomainException.notFound(
+                        org.raddatz.familienarchiv.exception.ErrorCode.DOCUMENT_NOT_FOUND, "Document not found: " + badId));
+
+        mockMvc.perform(patch("/api/documents/bulk")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(bulkBody(okId.toString(), badId.toString())))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.updated").value(1))
+                .andExpect(jsonPath("$.errors[0].id").value(badId.toString()))
+                .andExpect(jsonPath("$.errors[0].message").value(
+                        org.hamcrest.Matchers.containsString("not found")));
+    }
 }