feat: Drag-and-Drop-Reihenfolge, Station-Abschluss-Flow und UI-Verbesserungen

Lieferstationen-Dialog (Backend/Vaadin):
- Aufgaben per Drag & Drop neu anordnen, inkl. Drag-Handle, komprimierter
  Kachelansicht während des Drags und horizontaler Einfügelinie als Drop-Target
- Drop-Indikator wird unterdrückt, wenn der Drop keine Positionsänderung bewirken
  würde, und nach dem Abschluss clientseitig zuverlässig aufgeräumt
- Drag-Handle, Aufgabentyp-Label und Close-Button auf einheitlicher Position
  ausgerichtet; Abstände in der Kachel komprimiert

Station-Abschluss-Flow (Flutter-App + Backend):
- Neuer Button "Station abschließen" unter den Aufgaben; deaktiviert, solange
  Pflichtaufgaben offen sind, ansonsten aktiv (auch wenn nur optionale Aufgaben
  existieren)
- Hinweisdialog nach Erledigung der letzten Pflichtaufgabe sowie Warnung bei
  offenen optionalen Aufgaben vor dem Senden
- Neue station_completed-Nachricht (jobId, jobNumber, stationOrder,
  completedAt, hasIncompleteOptionalTasks) wird an den Server gesendet
- Backend: Auftrag wird nicht mehr automatisch beim Erledigen der letzten
  Pflichtaufgabe abgeschlossen, sondern erst beim Empfang der
  station_completed-Nachricht (neuer Handler in MessageController und
  MessagingConfig)

Aufgabenliste in der App:
- Farbcodierung optionaler Aufgaben entfernt; stattdessen vertikal zentrierter
  "Optional"-Chip am rechten Kartenrand

Weitere UI-Überarbeitungen über Login, Jobs, Chats, Settings, Aufgaben-Capture-
Screens, Offline-Banner und zugehörige Widgets.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/main/frontend/themes/votian-modern/styles.css

@@ -1143,6 +1143,8 @@ vaadin-grid-tree-toggle[expanded] .nav-expand-icon {
 
 .dialog-task-card {
   position: relative;
+  padding-top: calc(var(--lumo-space-m) + 5px) !important;
+  gap: calc(var(--lumo-space-m) / 16) !important;
   transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
 }
 
@@ -1152,14 +1154,112 @@ vaadin-grid-tree-toggle[expanded] .nav-expand-icon {
   border-color: rgba(37, 99, 235, 0.24);
 }
 
-.dialog-floating-delete {
+.dialog-task-card.drag-over-top::before,
+.dialog-task-card.drag-over-bottom::after {
+  content: "";
   position: absolute;
-  top: 0.65rem;
-  right: 0.65rem;
-  z-index: 10;
+  left: 0;
+  right: 0;
+  height: 3px;
+  background: var(--lumo-primary-color);
+  border-radius: 2px;
+  z-index: 20;
+  pointer-events: none;
+  box-shadow: 0 0 6px rgba(37, 99, 235, 0.45);
+}
+
+.dialog-task-card.drag-over-top::before {
+  top: calc(-0.5 * var(--lumo-space-m) - 1.5px);
+}
+
+.dialog-task-card.drag-over-bottom::after {
+  bottom: calc(-0.5 * var(--lumo-space-m) - 1.5px);
+}
+
+.dialog-task-card.dragging {
+  opacity: 0.35;
+  transform: scale(0.96);
+  box-shadow: none;
+}
+
+/* Compressed cards during reorder drag */
+.tasks-reordering .dialog-task-card {
+  padding: 0.4rem 0.8rem !important;
+  transition: padding 0.2s ease, max-height 0.2s ease;
+}
+
+.tasks-reordering .dialog-task-card:hover {
+  transform: none;
+}
+
+.tasks-reordering .dialog-task-config,
+.tasks-reordering .dialog-floating-delete,
+.tasks-reordering .dialog-task-drag-handle {
+  display: none;
+}
+
+.tasks-reordering .dialog-task-card vaadin-combo-box {
+  display: none;
+}
+
+.dialog-task-summary {
+  display: none;
+  align-items: center;
+  gap: 0.5rem;
+  font-size: var(--lumo-font-size-s);
+  color: var(--lumo-body-text-color);
+  font-weight: 500;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.dialog-task-summary .task-type-label {
+  color: var(--lumo-primary-color);
+  font-weight: 600;
+}
+
+.dialog-task-summary .task-desc-label {
+  color: var(--lumo-secondary-text-color);
+  font-weight: 400;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.tasks-reordering .dialog-task-summary {
+  display: flex;
+}
+
+.dialog-task-card[draggable="true"] {
+  cursor: grab;
+}
+
+.dialog-task-drag-handle {
+  cursor: grab;
+  color: var(--lumo-secondary-text-color);
   padding: 0.2rem;
   min-width: 1.7rem;
   min-height: 1.7rem;
+  flex-shrink: 0;
+  position: absolute;
+  top: -5px;
+  left: 15px;
+  z-index: 10;
+}
+
+.dialog-task-drag-handle:hover {
+  color: var(--lumo-primary-color);
+}
+
+.dialog-floating-delete {
+  padding: 0.2rem;
+  min-width: 1.7rem;
+  min-height: 1.7rem;
+  flex-shrink: 0;
+  position: absolute;
+  top: -5px;
+  right: 15px;
+  z-index: 10;
 }
 
 .inline-caption,

backend/src/main/java/de/assecutor/votianlt/controller/MessageController.java

@@ -375,7 +375,9 @@ public class MessageController {
                 String taskType = task.getTaskType() != null ? task.getTaskType().toString() : "Unknown";
                 String completedBy = task.getCompletedBy() != null ? task.getCompletedBy() : "Unknown";
                 emailService.sendTaskCompletionNotification(jobId, taskType, taskIdStr, completedBy);
-                checkAndHandleJobCompletion(jobId, completedBy);
+                // Job completion is no longer auto-triggered by task completion.
+                // It is now driven by explicit station_completed messages from the app
+                // (see handleStationCompleted).
             } catch (Exception e) {
                 // Ignore email notification errors
             }
@@ -430,6 +432,47 @@ public class MessageController {
         }
     }
 
+    /**
+     * Handle station completion message from app. Client sends to
+     * /server/station_completed with payload:
+     * {
+     *   "jobId": "jobnum:ABC123",
+     *   "jobNumber": "ABC123",
+     *   "stationOrder": 0,
+     *   "completedAt": "2026-04-13T12:34:56.789Z",
+     *   "hasIncompleteOptionalTasks": false
+     * }
+     *
+     * The job is marked as completed once this message is received and all
+     * mandatory tasks across all stations are completed.
+     */
+    public void handleStationCompleted(String appUserId, Map<String, Object> payload) {
+        try {
+            String jobNumber = payload.get("jobNumber") != null ? payload.get("jobNumber").toString() : null;
+            if (jobNumber == null || jobNumber.isBlank()) {
+                log.warn("[STATION] station_completed without jobNumber");
+                return;
+            }
+
+            Optional<Job> jobOpt = jobRepository.findByJobNumber(jobNumber);
+            if (jobOpt.isEmpty()) {
+                log.warn("[STATION] Job with jobNumber {} not found", jobNumber);
+                return;
+            }
+
+            ObjectId jobId = jobOpt.get().getId();
+            String completedBy = appUserId != null ? appUserId : "Unknown";
+
+            log.info("[STATION] station_completed received for jobNumber={}, stationOrder={}", jobNumber,
+                    payload.get("stationOrder"));
+
+            checkAndHandleJobCompletion(jobId, completedBy);
+            jobUpdateBroadcaster.broadcast(jobId);
+        } catch (Exception e) {
+            log.error("[STATION] Error handling station_completed: {}", e.getMessage());
+        }
+    }
+
     /**
      * Handle incoming message from a client via WebSocket. Client sends to
      * /server/message with payload: { "content": "message payload", "contentType":

backend/src/main/java/de/assecutor/votianlt/messaging/MessagingConfig.java

@@ -70,6 +70,14 @@ public class MessagingConfig {
             });
         });
 
+        // Station completion handler — marks a job as completed once all mandatory
+        // tasks have been finished and the app confirms the station is done.
+        webSocketService.registerMessageHandler("station_completed", (appUserId, payload) -> {
+            handlePayload(payload, payloadMap -> {
+                messageController.handleStationCompleted(appUserId, payloadMap);
+            });
+        });
+
         // Chat message handler
         webSocketService.registerMessageHandler("message", (appUserId, payload) -> {
             handlePayload(payload, payloadMap -> {

backend/src/main/java/de/assecutor/votianlt/pages/base/ui/component/DeliveryStationDialog.java

@@ -5,6 +5,10 @@ import com.vaadin.flow.component.button.ButtonVariant;
 import com.vaadin.flow.component.checkbox.Checkbox;
 import com.vaadin.flow.component.combobox.ComboBox;
 import com.vaadin.flow.component.dialog.Dialog;
+import com.vaadin.flow.component.dnd.DragSource;
+import com.vaadin.flow.component.dnd.DropEffect;
+import com.vaadin.flow.component.dnd.DropTarget;
+import com.vaadin.flow.component.dnd.EffectAllowed;
 import com.vaadin.flow.component.html.Div;
 import com.vaadin.flow.component.html.H3;
 import com.vaadin.flow.component.html.Span;
@@ -203,6 +207,7 @@ public class DeliveryStationDialog extends Dialog {
 
     private final List<BaseTask> tasksState = new ArrayList<>();
     private VerticalLayout tasksList;
+    private VerticalLayout draggedTaskContainer;
 
     private Span addressTabError;
     private Span tasksTabError;
@@ -866,6 +871,15 @@ public class DeliveryStationDialog extends Dialog {
         taskContainer.setSpacing(true);
         taskContainer.addClassName("dialog-task-card");
 
+        // Drag handle
+        Button dragHandle = new Button(new Icon(VaadinIcon.GRID_SMALL));
+        dragHandle.addThemeVariants(ButtonVariant.LUMO_TERTIARY);
+        dragHandle.addClassName("dialog-task-drag-handle");
+
+        // Compact summary shown during drag
+        HorizontalLayout summaryRow = createDragSummary("", "");
+        summaryRow.addClassName("dialog-task-summary");
+
         // Task type selection
         ComboBox<TaskType> taskTypeCombo = new ComboBox<>(translationHelper.getTranslation("addjob.tasks.tasktype"));
         taskTypeCombo.setItems(TaskType.values());
@@ -877,6 +891,7 @@ public class DeliveryStationDialog extends Dialog {
         VerticalLayout configContainer = new VerticalLayout();
         configContainer.setPadding(false);
         configContainer.setSpacing(true);
+        configContainer.addClassName("dialog-task-config");
 
         // Red X button positioned in top-right corner
         Button deleteXButton = new Button(new Icon(VaadinIcon.CLOSE_SMALL));
@@ -884,8 +899,14 @@ public class DeliveryStationDialog extends Dialog {
         deleteXButton.addClassName("dialog-floating-delete");
         deleteXButton.addClickListener(e -> removeTaskRow(taskContainer));
 
-        taskContainer.add(taskTypeCombo, configContainer);
-        taskContainer.add(deleteXButton);
+        HorizontalLayout headerRow = new HorizontalLayout(dragHandle, summaryRow, taskTypeCombo, deleteXButton);
+        headerRow.setAlignItems(FlexComponent.Alignment.START);
+        headerRow.setWidthFull();
+        headerRow.setFlexGrow(1, taskTypeCombo);
+
+        taskContainer.add(headerRow, configContainer);
+
+        setupDragAndDrop(taskContainer);
 
         // Create Task and add to state with correct order
         BaseTask task = new ConfirmationTask("");
@@ -896,6 +917,7 @@ public class DeliveryStationDialog extends Dialog {
 
         taskTypeCombo.setValue(TaskType.CONFIRMATION);
         updateTaskConfiguration(configContainer, currentTask[0]);
+        updateDragSummary(summaryRow, TaskType.CONFIRMATION, task);
 
         taskTypeCombo.addValueChangeListener(ev -> {
             TaskType selectedType = ev.getValue();
@@ -940,6 +962,7 @@ public class DeliveryStationDialog extends Dialog {
                 }
 
                 updateTaskConfiguration(configContainer, newTask);
+                updateDragSummary(summaryRow, selectedType, newTask);
             }
         });
 
@@ -953,6 +976,18 @@ public class DeliveryStationDialog extends Dialog {
         taskContainer.setSpacing(true);
         taskContainer.addClassName("dialog-task-card");
 
+        // Drag handle
+        Button dragHandle = new Button(new Icon(VaadinIcon.GRID_SMALL));
+        dragHandle.addThemeVariants(ButtonVariant.LUMO_TERTIARY);
+        dragHandle.addClassName("dialog-task-drag-handle");
+
+        // Compact summary shown during drag
+        TaskType initialTaskType = getTaskTypeFromTask(task);
+        HorizontalLayout summaryRow = createDragSummary(
+                initialTaskType != null ? initialTaskType.getDisplayName() : "",
+                task.getDescription() != null ? task.getDescription() : "");
+        summaryRow.addClassName("dialog-task-summary");
+
         ComboBox<TaskType> taskTypeCombo = new ComboBox<>(translationHelper.getTranslation("addjob.tasks.tasktype"));
         taskTypeCombo.setItems(TaskType.values());
         taskTypeCombo.setItemLabelGenerator(TaskType::getDisplayName);
@@ -962,21 +997,27 @@ public class DeliveryStationDialog extends Dialog {
         VerticalLayout configContainer = new VerticalLayout();
         configContainer.setPadding(false);
         configContainer.setSpacing(true);
+        configContainer.addClassName("dialog-task-config");
 
         Button deleteXButton = new Button(new Icon(VaadinIcon.CLOSE_SMALL));
         deleteXButton.addThemeVariants(ButtonVariant.LUMO_ERROR, ButtonVariant.LUMO_TERTIARY);
         deleteXButton.addClassName("dialog-floating-delete");
         deleteXButton.addClickListener(e -> removeTaskRow(taskContainer));
 
-        taskContainer.add(taskTypeCombo, configContainer);
-        taskContainer.add(deleteXButton);
+        HorizontalLayout headerRow = new HorizontalLayout(dragHandle, summaryRow, taskTypeCombo, deleteXButton);
+        headerRow.setAlignItems(FlexComponent.Alignment.START);
+        headerRow.setWidthFull();
+        headerRow.setFlexGrow(1, taskTypeCombo);
+
+        taskContainer.add(headerRow, configContainer);
+
+        setupDragAndDrop(taskContainer);
 
         final BaseTask[] currentTask = { task };
 
         // Set the combo value BEFORE registering the listener
-        TaskType taskType = getTaskTypeFromTask(task);
-        if (taskType != null) {
-            taskTypeCombo.setValue(taskType);
+        if (initialTaskType != null) {
+            taskTypeCombo.setValue(initialTaskType);
         }
 
         // Register the listener for user-initiated type changes only
@@ -1021,11 +1062,13 @@ public class DeliveryStationDialog extends Dialog {
                 }
 
                 updateTaskConfiguration(configContainer, newTask);
+                updateDragSummary(summaryRow, selectedType, newTask);
             }
         });
 
         // Render the UI with the loaded task
         updateTaskConfiguration(configContainer, task);
+        updateDragSummary(summaryRow, initialTaskType, task);
 
         tasksList.add(taskContainer);
         updateTaskDeleteAvailability();
@@ -1042,6 +1085,160 @@ public class DeliveryStationDialog extends Dialog {
         };
     }
 
+    private HorizontalLayout createDragSummary(String typeName, String description) {
+        Span typeLabel = new Span(typeName);
+        typeLabel.addClassName("task-type-label");
+        Span descLabel = new Span(description != null && !description.isBlank() ? " — " + description : "");
+        descLabel.addClassName("task-desc-label");
+        HorizontalLayout layout = new HorizontalLayout(typeLabel, descLabel);
+        layout.setSpacing(false);
+        layout.setPadding(false);
+        layout.setAlignItems(FlexComponent.Alignment.CENTER);
+        return layout;
+    }
+
+    private void updateDragSummary(HorizontalLayout summaryRow, TaskType taskType, BaseTask task) {
+        summaryRow.getChildren()
+                .filter(Span.class::isInstance)
+                .map(Span.class::cast)
+                .forEach(span -> {
+                    if (span.getClassNames().contains("task-type-label")) {
+                        span.setText(taskType != null ? taskType.getDisplayName() : "");
+                    } else if (span.getClassNames().contains("task-desc-label")) {
+                        String desc = task.getDescription();
+                        span.setText(desc != null && !desc.isBlank() ? " — " + desc : "");
+                    }
+                });
+    }
+
+    private void clearAllDropIndicators() {
+        if (tasksList == null) {
+            return;
+        }
+        tasksList.removeClassName("tasks-reordering");
+        tasksList.getChildren()
+                .filter(VerticalLayout.class::isInstance)
+                .map(VerticalLayout.class::cast)
+                .forEach(c -> {
+                    c.removeClassName("drag-over-top");
+                    c.removeClassName("drag-over-bottom");
+                    c.removeClassName("dragging");
+                });
+    }
+
+    private void setupDragAndDrop(VerticalLayout taskContainer) {
+        DragSource<VerticalLayout> dragSource = DragSource.create(taskContainer);
+        dragSource.setEffectAllowed(EffectAllowed.MOVE);
+        dragSource.addDragStartListener(e -> {
+            draggedTaskContainer = taskContainer;
+            taskContainer.addClassName("dragging");
+            if (tasksList != null) {
+                // Update all summaries with latest description values before compressing
+                List<com.vaadin.flow.component.Component> rows = tasksList.getChildren().toList();
+                for (int i = 0; i < rows.size() && i < tasksState.size(); i++) {
+                    if (rows.get(i) instanceof VerticalLayout row) {
+                        row.getChildren()
+                                .filter(HorizontalLayout.class::isInstance)
+                                .map(HorizontalLayout.class::cast)
+                                .findFirst()
+                                .ifPresent(headerRow -> headerRow.getChildren()
+                                        .filter(HorizontalLayout.class::isInstance)
+                                        .map(HorizontalLayout.class::cast)
+                                        .filter(c -> c.getClassNames().contains("dialog-task-summary"))
+                                        .findFirst()
+                                        .ifPresent(summary -> {
+                                            int idx = rows.indexOf(row);
+                                            if (idx >= 0 && idx < tasksState.size()) {
+                                                BaseTask t = tasksState.get(idx);
+                                                TaskType tt = getTaskTypeFromTask(t);
+                                                updateDragSummary(summary, tt, t);
+                                            }
+                                        }));
+                    }
+                }
+                tasksList.addClassName("tasks-reordering");
+            }
+        });
+        dragSource.addDragEndListener(e -> {
+            draggedTaskContainer = null;
+            clearAllDropIndicators();
+        });
+
+        DropTarget<VerticalLayout> dropTarget = DropTarget.create(taskContainer);
+        dropTarget.setDropEffect(DropEffect.MOVE);
+        dropTarget.addDropListener(e -> {
+            if (draggedTaskContainer != null && draggedTaskContainer != taskContainer) {
+                moveTaskRow(draggedTaskContainer, taskContainer);
+            }
+            clearAllDropIndicators();
+        });
+
+        // Client-side drag events with position detection and no-op suppression
+        taskContainer.getElement().executeJs(
+                "const el = this;"
+                        + "function clearIndicators() {"
+                        + "  var p = el.parentElement;"
+                        + "  if (p) p.querySelectorAll('.drag-over-top, .drag-over-bottom').forEach("
+                        + "    function(c) { c.classList.remove('drag-over-top', 'drag-over-bottom'); });"
+                        + "}"
+                        + "function getSiblings() {"
+                        + "  return Array.from(el.parentElement.children).filter("
+                        + "    function(c) { return c.classList.contains('dialog-task-card'); });"
+                        + "}"
+                        + "el.addEventListener('dragstart', function() {"
+                        + "  el.parentElement.__draggedEl = el;"
+                        + "});"
+                        + "el.addEventListener('dragend', function() {"
+                        + "  el.parentElement.__draggedEl = null;"
+                        + "});"
+                        + "el.addEventListener('dragover', function(e) {"
+                        + "  e.preventDefault();"
+                        + "  var dragged = el.parentElement.__draggedEl;"
+                        + "  if (!dragged || dragged === el) { clearIndicators(); return; }"
+                        + "  var cards = getSiblings();"
+                        + "  var dragIdx = cards.indexOf(dragged);"
+                        + "  var myIdx = cards.indexOf(el);"
+                        + "  clearIndicators();"
+                        + "  var rect = el.getBoundingClientRect();"
+                        + "  var midY = rect.top + rect.height / 2;"
+                        + "  if (e.clientY < midY) {"
+                        + "    if (myIdx !== dragIdx + 1) el.classList.add('drag-over-top');"
+                        + "  } else {"
+                        + "    if (myIdx !== dragIdx - 1) el.classList.add('drag-over-bottom');"
+                        + "  }"
+                        + "});"
+                        + "el.addEventListener('dragleave', function() {"
+                        + "  el.classList.remove('drag-over-top', 'drag-over-bottom');"
+                        + "});"
+                        + "el.addEventListener('drop', function() {"
+                        + "  clearIndicators();"
+                        + "});");
+    }
+
+    private void moveTaskRow(VerticalLayout source, VerticalLayout target) {
+        List<com.vaadin.flow.component.Component> rows = tasksList.getChildren().toList();
+        int fromIndex = rows.indexOf(source);
+        int toIndex = rows.indexOf(target);
+        if (fromIndex < 0 || toIndex < 0 || fromIndex == toIndex) {
+            return;
+        }
+
+        // Reorder tasksState
+        BaseTask movedTask = tasksState.remove(fromIndex);
+        tasksState.add(toIndex, movedTask);
+
+        // Reorder UI: remove all, re-add in new order
+        List<com.vaadin.flow.component.Component> rowList = new ArrayList<>(rows);
+        com.vaadin.flow.component.Component movedRow = rowList.remove(fromIndex);
+        rowList.add(toIndex, movedRow);
+
+        tasksList.removeAll();
+        rowList.forEach(tasksList::add);
+
+        // Update taskOrder values
+        reorderTasksAfterDeletion();
+    }
+
     private void reorderTasksAfterDeletion() {
         for (int i = 0; i < tasksState.size(); i++) {
             BaseTask task = tasksState.get(i);
@@ -1094,11 +1291,15 @@ public class DeliveryStationDialog extends Dialog {
                 .filter(VerticalLayout.class::isInstance)
                 .map(VerticalLayout.class::cast)
                 .forEach(taskContainer -> taskContainer.getChildren()
-                        .filter(Button.class::isInstance)
-                        .map(Button.class::cast)
-                        .filter(button -> button.getClassNames().contains("dialog-floating-delete"))
+                        .filter(HorizontalLayout.class::isInstance)
+                        .map(HorizontalLayout.class::cast)
                         .findFirst()
-                        .ifPresent(button -> button.setEnabled(deletable)));
+                        .ifPresent(headerRow -> headerRow.getChildren()
+                                .filter(Button.class::isInstance)
+                                .map(Button.class::cast)
+                                .filter(button -> button.getClassNames().contains("dialog-floating-delete"))
+                                .findFirst()
+                                .ifPresent(button -> button.setEnabled(deletable))));
     }
 
     private void updateTaskConfiguration(VerticalLayout configContainer, BaseTask task) {