fix(document): enlarge auto-title helper to 14px and assert its localized text (#726)

Bumps the title helper from text-xs (12px) to text-sm (14px) for the 60+ audience (FR-005
prefers a larger size than the field hints) and tightens the component test to assert the
actual localized string and the 14px class — addresses Leonie's and Sara's review notes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -431,7 +431,11 @@ public class DocumentService {
             doc.setScriptType(dto.getScriptType());
         }
 
-        // 4. Datei austauschen (nur wenn eine neue ausgewählt wurde)
+        // 4. Datei austauschen (nur wenn eine neue ausgewählt wurde).
+        // NB (#726): this reassigns originalFilename to the uploaded file's name. The title's index
+        // segment is originalFilename, so after a replace the stored title no longer matches
+        // build(currentState) and the row is treated as manual — neither save-time nor backfill
+        // rewrites it. Accepted fail-safe (ADR-031), and autoTitleBefore was already captured above.
         boolean fileReplaced = newFile != null && !newFile.isEmpty();
         if (fileReplaced) {
             FileService.UploadResult upload = fileService.uploadFile(newFile, newFile.getOriginalFilename());
@@ -479,44 +483,49 @@ public class DocumentService {
     }
 
     /**
-     * The document state the regenerated title is built from, mirroring {@code updateDocument}'s
-     * setter asymmetry exactly: {@code documentDate}/{@code location} are overwritten from the DTO
-     * (a null value clears the field), while precision/end/raw are taken from the DTO only when
-     * non-null and otherwise kept from the stored entity (see {@link #applyDatePrecision}). The
-     * index ({@code originalFilename}) is never touched by a metadata edit. A mismatch here would
-     * silently produce a wrong label, so it is kept lock-step with the real setters.
+     * The document state the regenerated title is built from. It is composed from the SAME
+     * resolvers the real setters use — {@code documentDate}/{@code location} overwritten from the
+     * DTO (a null value clears the field), precision/end/raw resolved skip-null via
+     * {@link #effectivePrecision}/{@link #effectiveMetaDateEnd}/{@link #effectiveMetaDateRaw} — so
+     * the projection cannot drift from {@link #updateDocument}. The index ({@code originalFilename})
+     * is never touched by a metadata edit.
      */
     private Document projectedState(Document doc, DocumentUpdateDTO dto) {
         return Document.builder()
                 .originalFilename(doc.getOriginalFilename())
                 .documentDate(dto.getDocumentDate())
                 .location(dto.getLocation())
-                .metaDatePrecision(dto.getMetaDatePrecision() != null
-                        ? dto.getMetaDatePrecision() : doc.getMetaDatePrecision())
-                .metaDateEnd(dto.getMetaDateEnd() != null
-                        ? dto.getMetaDateEnd() : doc.getMetaDateEnd())
-                .metaDateRaw(dto.getMetaDateRaw() != null
-                        ? dto.getMetaDateRaw() : doc.getMetaDateRaw())
+                .metaDatePrecision(effectivePrecision(doc, dto))
+                .metaDateEnd(effectiveMetaDateEnd(doc, dto))
+                .metaDateRaw(effectiveMetaDateRaw(doc, dto))
                 .build();
     }
 
     /**
-     * Applies the three date-precision fields only when the DTO carries them.
-     * A null field means "not submitted" — overwriting the stored value with null
-     * would fabricate a precision the user never chose, the exact dishonesty #666
-     * exists to prevent. A row with a genuinely-unknown precision must keep it when
-     * an unrelated edit (e.g. a location typo) is saved.
+     * Applies the three date-precision fields skip-null: a null DTO field means "not submitted",
+     * so the stored value is kept rather than overwritten with null — which would fabricate a
+     * precision the user never chose, the exact dishonesty #666 exists to prevent. Expressed via
+     * the shared {@code effective*} resolvers so {@link #projectedState} stays lock-step (writing
+     * the stored value back when the DTO omits a field is a harmless no-op).
      */
     private void applyDatePrecision(Document doc, DocumentUpdateDTO dto) {
-        if (dto.getMetaDatePrecision() != null) {
-            doc.setMetaDatePrecision(dto.getMetaDatePrecision());
-        }
-        if (dto.getMetaDateEnd() != null) {
-            doc.setMetaDateEnd(dto.getMetaDateEnd());
-        }
-        if (dto.getMetaDateRaw() != null) {
-            doc.setMetaDateRaw(dto.getMetaDateRaw());
-        }
+        doc.setMetaDatePrecision(effectivePrecision(doc, dto));
+        doc.setMetaDateEnd(effectiveMetaDateEnd(doc, dto));
+        doc.setMetaDateRaw(effectiveMetaDateRaw(doc, dto));
+    }
+
+    // Skip-null date-field resolution shared by applyDatePrecision (the real setters) and
+    // projectedState (the title projection) — the single rule keeps them from diverging (#726).
+    private static DatePrecision effectivePrecision(Document doc, DocumentUpdateDTO dto) {
+        return dto.getMetaDatePrecision() != null ? dto.getMetaDatePrecision() : doc.getMetaDatePrecision();
+    }
+
+    private static LocalDate effectiveMetaDateEnd(Document doc, DocumentUpdateDTO dto) {
+        return dto.getMetaDateEnd() != null ? dto.getMetaDateEnd() : doc.getMetaDateEnd();
+    }
+
+    private static String effectiveMetaDateRaw(Document doc, DocumentUpdateDTO dto) {
+        return dto.getMetaDateRaw() != null ? dto.getMetaDateRaw() : doc.getMetaDateRaw();
     }
 
     /**

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

@@ -371,6 +371,43 @@ class DocumentServiceTest {
         assertThat(stored.getTitle()).isEqualTo("C-0029 – Frühling 1943");
     }
 
+    @Test
+    void updateDocument_carriesStoredPrecisionAndRaw_whenDtoOmitsThem() throws Exception {
+        // Only the year changes; precision/end/raw are omitted from the DTO, so projectedState
+        // must carry them from the entity (exercises the skip-null effective* resolvers).
+        Document stored = makeStored("C-0029", LocalDate.of(1943, 4, 1), DatePrecision.SEASON, null);
+        stored.setMetaDateRaw("Frühling 1943");
+        stored.setTitle(documentTitleFactory.build(stored)); // "C-0029 – Frühling 1943"
+        DocumentUpdateDTO dto = editDto(stored.getTitle(), LocalDate.of(1944, 4, 1), null, null);
+
+        runUpdate(stored, dto);
+
+        assertThat(stored.getTitle()).isEqualTo("C-0029 – Frühling 1944");
+    }
+
+    @Test
+    void updateDocument_roundTripsRangeLabel_atSaveTime() throws Exception {
+        Document stored = Document.builder()
+                .id(UUID.randomUUID())
+                .originalFilename("C-0029")
+                .documentDate(LocalDate.of(1917, 1, 10))
+                .metaDatePrecision(DatePrecision.RANGE)
+                .metaDateEnd(LocalDate.of(1917, 1, 11))
+                .receivers(new HashSet<>())
+                .tags(new HashSet<>())
+                .build();
+        stored.setTitle(documentTitleFactory.build(stored)); // "C-0029 – 10.–11. Jan. 1917"
+        DocumentUpdateDTO dto = new DocumentUpdateDTO();
+        dto.setTitle(stored.getTitle());
+        dto.setDocumentDate(LocalDate.of(1918, 1, 10));
+        dto.setMetaDatePrecision(DatePrecision.RANGE);
+        dto.setMetaDateEnd(LocalDate.of(1918, 1, 11));
+
+        runUpdate(stored, dto);
+
+        assertThat(stored.getTitle()).isEqualTo("C-0029 – 10.–11. Jan. 1918");
+    }
+
     @Test
     void updateDocument_doesNotRegenerateToBlank_whenSubmittedTitleEmpty() throws Exception {
         Document stored = makeStored("C-0029", LocalDate.of(1928, 1, 1), DatePrecision.YEAR, "Berlin");

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

@@ -52,7 +52,7 @@ class DocumentTitleBackfillIntegrationTest {
 
         int count = documentService.backfillTitles();
 
-        assertThat(count).isGreaterThanOrEqualTo(1);
+        assertThat(count).isEqualTo(1); // exactly the one stale row seeded (clean test DB)
         assertThat(documentRepository.findById(stale.getId()).orElseThrow().getTitle())
                 .isEqualTo("C-0029 – 1928 – Berlin");
     }

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

@@ -118,6 +118,30 @@ class DocumentTitleBackfillMatcherTest {
         assertThat(overwritable("Ganz anderer Titel", null)).isFalse();
     }
 
+    // ─── near-miss: shapes that look almost machine-built but are not ──────────
+
+    @Test
+    void ascii_hyphen_instead_of_en_dash_separator_is_skipped() {
+        // The separator is " – " (en dash); a plain " - " is not the machine separator.
+        assertThat(overwritable("C-0029 - 1916", null)).isFalse();
+    }
+
+    @Test
+    void date_label_without_separator_before_trailing_text_is_skipped() {
+        // "1916 Berlin" is not a date label and is not joined by " – "; prose, not machine.
+        assertThat(overwritable("C-0029 – 1916 Berlin", null)).isFalse();
+    }
+
+    @Test
+    void year_with_trailing_letters_is_not_a_year_label() {
+        assertThat(overwritable("C-0029 – 1916er Brief", null)).isFalse();
+    }
+
+    @Test
+    void index_immediately_followed_by_text_without_separator_is_skipped() {
+        assertThat(overwritable("C-0029x – 1916", null)).isFalse();
+    }
+
     // ─── fail-closed guards ───────────────────────────────────────────────────
 
     @Test

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

@@ -71,6 +71,13 @@ class DocumentTitleFactoryTest {
         assertThat(factory.build(d)).isEqualTo("C-0029 – 1928");
     }
 
+    @Test
+    void bare_document_with_null_index_builds_empty_string_not_npe() {
+        // originalFilename is NOT NULL in production; the guard keeps a synthetic/partial entity
+        // from tripping StringBuilder(null) with an opaque NPE.
+        assertThat(factory.build(Document.builder().build())).isEqualTo("");
+    }
+
     @Test
     void day_precision_renders_the_full_german_label() {
         Document d = doc("C-0029")

frontend/src/lib/document/DescriptionSection.svelte

@@ -78,7 +78,7 @@ const titleValue = $derived(titleDirty ? currentTitle : suggestedTitle || curren
 					class="block w-full rounded border border-line p-2 text-sm shadow-sm focus:outline-none focus-visible:ring-2 focus-visible:ring-focus-ring"
 				/>
 				{#if showTitleHelp}
-					<p id="title-help" class="mt-1 text-xs text-ink-3">
+					<p id="title-help" class="mt-1 text-sm text-ink-3">
 						{m.form_helper_title_autogenerated()}
 					</p>
 				{/if}

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

@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, it } from 'vitest';
 import { cleanup, render } from 'vitest-browser-svelte';
 import DescriptionSection from './DescriptionSection.svelte';
+import { m } from '$lib/paraglide/messages.js';
 
 afterEach(() => cleanup());
 
@@ -57,11 +58,13 @@ describe('DescriptionSection — onMount seeding (Felix B1/B2 fix regression fen
 });
 
 describe('DescriptionSection — auto-generated title helper (FR-TITLE-005)', () => {
-	it('shows the helper and wires aria-describedby when showTitleHelp is set', async () => {
+	it('shows the helper with the localized text and wires aria-describedby when showTitleHelp is set', async () => {
 		render(DescriptionSection, { showTitleHelp: true });
 		const help = document.querySelector('#title-help') as HTMLElement;
 		expect(help).not.toBeNull();
-		expect(help.textContent?.trim().length ?? 0).toBeGreaterThan(0);
+		expect(help.textContent?.trim()).toBe(m.form_helper_title_autogenerated());
+		// ≥14px for the 60+ audience (FR-005 prefers a larger size than the 12px field hints).
+		expect(help.classList.contains('text-sm')).toBe(true);
 		const titleInput = document.querySelector('input#title') as HTMLInputElement;
 		expect(titleInput.getAttribute('aria-describedby')).toBe('title-help');
 	});