feat(quick-upload): pre-fill date and sender from structured filename

storeDocument() now uses the ParsedFilename record to also set
documentDate and sender on new quick-uploads. Sender lookup is
an exact case-insensitive first+last name match — no new persons
are created. Unmatched filenames behave as before.

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

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

@@ -28,6 +28,9 @@ public interface PersonRepository extends JpaRepository<Person, UUID> {
     // Lookup by full alias string, used during ODS mass import
     Optional<Person> findByAliasIgnoreCase(String alias);
 
+    // Exact first+last name match, used for filename-based sender lookup
+    Optional<Person> findByFirstNameIgnoreCaseAndLastNameIgnoreCase(String firstName, String lastName);
+
     // --- Correspondent queries ---
 
     @Query(value = """

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

@@ -63,9 +63,15 @@ public class DocumentService {
             document = existingDoc.get();
         } else {
             // New uploads from the drop zone always start as incomplete
+            ParsedFilename parsed = parseFilenameData(originalFilename);
+            Person sender = (parsed != null)
+                    ? personService.findByName(parsed.firstName(), parsed.lastName()).orElse(null)
+                    : null;
             document = Document.builder()
                     .originalFilename(originalFilename)
-                    .title(titleFromFilename(originalFilename))
+                    .title(parsed != null ? parsed.title() : stripExtension(originalFilename))
+                    .documentDate(parsed != null ? parsed.date() : null)
+                    .sender(sender)
                     .status(DocumentStatus.UPLOADED)
                     .metadataComplete(false)
                     .build();
@@ -356,29 +362,35 @@ public class DocumentService {
         return dot > 0 ? filename.substring(0, dot) : filename;
     }
 
+    private record ParsedFilename(LocalDate date, String firstName, String lastName) {
+        String title() {
+            String dateDisplay = String.format("%02d.%02d.%d",
+                    date.getDayOfMonth(), date.getMonthValue(), date.getYear());
+            return firstName + " " + lastName + " (" + dateDisplay + ")";
+        }
+    }
+
     /**
-     * Derives a human-readable title from a structured filename.
+     * Parses a structured filename into its date and name components.
      *
      * Algorithm: split stem on "_", identify the date token (first or last segment),
      * treat the outermost remaining segment as firstName, rest as lastName parts.
-     * Compound last names (e.g. "de_Gruyter") are handled naturally.
-     * Falls back to stripExtension for unrecognised filenames.
+     * Compound last names (e.g. "de_Gruyter") are supported naturally.
+     * Returns null for unrecognised filenames.
      *
      * Examples:
-     *   18881025_de_Gruyter_Walter.pdf  → "Walter de Gruyter (25.10.1888)"
-     *   1965-03-12_Mueller_Hans.pdf     → "Hans Mueller (12.03.1965)"
-     *   Mueller_Hans_19650312.pdf       → "Hans Mueller (12.03.1965)"
+     *   18881025_de_Gruyter_Walter.pdf  → date=1888-10-25, firstName=Walter, lastName=de Gruyter
+     *   1965-03-12_Mueller_Hans.pdf     → date=1965-03-12, firstName=Hans,   lastName=Mueller
+     *   Mueller_Hans_19650312.pdf       → date=1965-03-12, firstName=Hans,   lastName=Mueller
      */
-    static String titleFromFilename(String filename) {
+    private static ParsedFilename parseFilenameData(String filename) {
         if (filename == null) return null;
-
         int dot = filename.lastIndexOf('.');
-        if (dot < 0) return stripExtension(filename);
+        if (dot < 0) return null;
         String stem = filename.substring(0, dot);
 
         String[] parts = stem.split("_", -1);
-        // Minimum: date + at least one lastName segment + firstName
-        if (parts.length < 3) return stripExtension(filename);
+        if (parts.length < 3) return null;
 
         String dateIso;
         String[] nameParts;
@@ -389,23 +401,26 @@ public class DocumentService {
             nameParts = Arrays.copyOfRange(parts, 1, parts.length);
         } else {
             String dateFromLast = tryParseDate(parts[parts.length - 1]);
-            if (dateFromLast == null) return stripExtension(filename);
+            if (dateFromLast == null) return null;
             dateIso = dateFromLast;
             nameParts = Arrays.copyOfRange(parts, 0, parts.length - 1);
         }
 
-        if (nameParts.length < 2) return stripExtension(filename);
-
+        if (nameParts.length < 2) return null;
         for (String p : nameParts) {
-            if (!p.matches("\\p{L}+")) return stripExtension(filename);
+            if (!p.matches("\\p{L}+")) return null;
         }
 
         String firstName = nameParts[nameParts.length - 1];
         String lastName = String.join(" ", Arrays.copyOfRange(nameParts, 0, nameParts.length - 1));
+        return new ParsedFilename(LocalDate.parse(dateIso), firstName, lastName);
+    }
 
-        LocalDate date = LocalDate.parse(dateIso);
-        String dateDisplay = String.format("%02d.%02d.%d", date.getDayOfMonth(), date.getMonthValue(), date.getYear());
-        return firstName + " " + lastName + " (" + dateDisplay + ")";
+    // Used by tests and as a public utility; delegates to parseFilenameData.
+    static String titleFromFilename(String filename) {
+        if (filename == null) return null;
+        ParsedFilename parsed = parseFilenameData(filename);
+        return parsed != null ? parsed.title() : stripExtension(filename);
     }
 
     private static String tryParseDate(String s) {

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

@@ -1,6 +1,7 @@
 package org.raddatz.familienarchiv.service;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 
 import org.raddatz.familienarchiv.dto.PersonUpdateDTO;
@@ -42,6 +43,10 @@ public class PersonService {
         return personRepository.findAllById(ids);
     }
 
+    public Optional<Person> findByName(String firstName, String lastName) {
+        return personRepository.findByFirstNameIgnoreCaseAndLastNameIgnoreCase(firstName, lastName);
+    }
+
     @Transactional
     public Person findOrCreateByAlias(String rawName) {
         String alias = rawName.trim();

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

@@ -10,6 +10,7 @@ import org.raddatz.familienarchiv.dto.DocumentUpdateDTO;
 import org.raddatz.familienarchiv.exception.DomainException;
 import org.raddatz.familienarchiv.model.Document;
 import org.raddatz.familienarchiv.model.DocumentStatus;
+import org.raddatz.familienarchiv.model.Person;
 import org.raddatz.familienarchiv.model.Tag;
 import org.raddatz.familienarchiv.repository.DocumentRepository;
 import org.springframework.data.domain.Sort;
@@ -419,6 +420,53 @@ class DocumentServiceTest {
         assertThat(existing.isMetadataComplete()).isTrue();
     }
 
+    @Test
+    void storeDocument_parsesDateFromFilename_forNewDocument() throws Exception {
+        MockMultipartFile file = new MockMultipartFile("file", "19650312_Mueller_Hans.pdf", "application/pdf", new byte[]{1});
+        when(documentRepository.findFirstByOriginalFilename(any())).thenReturn(Optional.empty());
+        when(documentRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(fileService.uploadFile(any(), any())).thenReturn(new FileService.UploadResult("path", "hash"));
+        when(personService.findByName(any(), any())).thenReturn(Optional.empty());
+
+        ArgumentCaptor<Document> captor = ArgumentCaptor.forClass(Document.class);
+        documentService.storeDocument(file);
+
+        verify(documentRepository).save(captor.capture());
+        assertThat(captor.getValue().getDocumentDate()).isEqualTo(java.time.LocalDate.of(1965, 3, 12));
+        assertThat(captor.getValue().getTitle()).isEqualTo("Hans Mueller (12.03.1965)");
+    }
+
+    @Test
+    void storeDocument_setsSender_whenPersonExistsForParsedName() throws Exception {
+        MockMultipartFile file = new MockMultipartFile("file", "18881025_de_Gruyter_Walter.pdf", "application/pdf", new byte[]{1});
+        Person walter = Person.builder().id(UUID.randomUUID()).firstName("Walter").lastName("de Gruyter").build();
+        when(documentRepository.findFirstByOriginalFilename(any())).thenReturn(Optional.empty());
+        when(documentRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(fileService.uploadFile(any(), any())).thenReturn(new FileService.UploadResult("path", "hash"));
+        when(personService.findByName("Walter", "de Gruyter")).thenReturn(Optional.of(walter));
+
+        ArgumentCaptor<Document> captor = ArgumentCaptor.forClass(Document.class);
+        documentService.storeDocument(file);
+
+        verify(documentRepository).save(captor.capture());
+        assertThat(captor.getValue().getSender()).isEqualTo(walter);
+    }
+
+    @Test
+    void storeDocument_leavesSenderNull_whenPersonNotFound() throws Exception {
+        MockMultipartFile file = new MockMultipartFile("file", "19650312_Mueller_Hans.pdf", "application/pdf", new byte[]{1});
+        when(documentRepository.findFirstByOriginalFilename(any())).thenReturn(Optional.empty());
+        when(documentRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(fileService.uploadFile(any(), any())).thenReturn(new FileService.UploadResult("path", "hash"));
+        when(personService.findByName(any(), any())).thenReturn(Optional.empty());
+
+        ArgumentCaptor<Document> captor = ArgumentCaptor.forClass(Document.class);
+        documentService.storeDocument(file);
+
+        verify(documentRepository).save(captor.capture());
+        assertThat(captor.getValue().getSender()).isNull();
+    }
+
     // ─── createDocument metadataComplete ─────────────────────────────────────
 
     @Test