feat: Etiketten-Editor erheblich verbessert - Import/Export, Zoom, Duplizieren

- Vorlage als JSON exportieren/importieren, damit man sich ein Etikett
  auch per KI erstellen und danach importieren kann
- Zoom-Regler fuer den Canvas (50-200%), da Etikettgroessen stark variieren
- X/Y-Positionsfelder pro Element fuer praezise Platzierung statt nur Drag
- Element duplizieren-Button
- Entf/Backspace loescht das ausgewaehlte Element

ApiCore-Frontend/src/app/(app)/settings/label-templates/designer/element-properties-panel.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { Bold, Italic, Trash2 } from "lucide-react";
+import { Bold, Copy, Italic, Trash2 } from "lucide-react";
 import {
   LabelElement,
   LabelFontFamily,
@@ -36,12 +36,14 @@ interface ElementPropertiesPanelProps {
   element: LabelElement;
   onChange: (patch: Partial<LabelElement>) => void;
   onDelete: () => void;
+  onDuplicate: () => void;
 }
 
 export function ElementPropertiesPanel({
   element,
   onChange,
   onDelete,
+  onDuplicate,
 }: ElementPropertiesPanelProps) {
   return (
     <div className="flex flex-col gap-4">
@@ -49,9 +51,37 @@ export function ElementPropertiesPanel({
         <p className="text-sm font-medium text-muted-foreground">
           {element.type === "text" ? "Text" : element.type === "qrCode" ? "QR-Code" : element.type === "image" ? "Bild" : "Linie"}
         </p>
-        <Button type="button" variant="ghost" size="icon-sm" onClick={onDelete}>
-          <Trash2 className="size-3.5 text-destructive" />
-        </Button>
+        <div className="flex gap-1">
+          <Button type="button" variant="ghost" size="icon-sm" onClick={onDuplicate} title="Duplizieren">
+            <Copy className="size-3.5" />
+          </Button>
+          <Button type="button" variant="ghost" size="icon-sm" onClick={onDelete} title="Löschen">
+            <Trash2 className="size-3.5 text-destructive" />
+          </Button>
+        </div>
+      </div>
+
+      <div className="flex gap-3">
+        <div className="flex flex-1 flex-col gap-2">
+          <Label htmlFor="element-x">X (mm)</Label>
+          <Input
+            id="element-x"
+            type="number"
+            inputMode="decimal"
+            value={element.x}
+            onChange={(event) => onChange({ x: Number(event.target.value) })}
+          />
+        </div>
+        <div className="flex flex-1 flex-col gap-2">
+          <Label htmlFor="element-y">Y (mm)</Label>
+          <Input
+            id="element-y"
+            type="number"
+            inputMode="decimal"
+            value={element.y}
+            onChange={(event) => onChange({ y: Number(event.target.value) })}
+          />
+        </div>
       </div>
 
       {element.type === "text" ? <TextFields element={element} onChange={onChange} /> : null}

ApiCore-Frontend/src/app/(app)/settings/label-templates/designer/label-canvas.tsx

@@ -8,7 +8,7 @@ import {
 } from "@/lib/label-templates/types";
 import { cn } from "@/lib/utils";
 
-export const CANVAS_SCALE = 4; // px per mm
+export const BASE_SCALE = 4; // px per mm at 100% zoom
 const PT_TO_MM = 25.4 / 72;
 const MIN_SIZE_MM = 5;
 
@@ -27,6 +27,7 @@ interface LabelCanvasProps {
   heightMm: number;
   elements: LabelElement[];
   selectedId: string | null;
+  zoom?: number;
   onSelect: (id: string | null) => void;
   onChangeElement: (id: string, patch: Partial<LabelElement>) => void;
 }
@@ -36,9 +37,12 @@ export function LabelCanvas({
   heightMm,
   elements,
   selectedId,
+  zoom = 1,
   onSelect,
   onChangeElement,
 }: LabelCanvasProps) {
+  const scale = BASE_SCALE * zoom;
+
   function startDrag(
     event: ReactPointerEvent,
     element: LabelElement,
@@ -52,8 +56,8 @@ export function LabelCanvas({
     const origin = element;
 
     function onMove(moveEvent: PointerEvent) {
-      const dxMm = (moveEvent.clientX - startX) / CANVAS_SCALE;
-      const dyMm = (moveEvent.clientY - startY) / CANVAS_SCALE;
+      const dxMm = (moveEvent.clientX - startX) / scale;
+      const dyMm = (moveEvent.clientY - startY) / scale;
 
       if (mode === "move") {
         onChangeElement(origin.id, {
@@ -92,13 +96,14 @@ export function LabelCanvas({
   return (
     <div
       className="relative overflow-hidden rounded-lg border border-dashed border-border bg-white shadow-sm"
-      style={{ width: widthMm * CANVAS_SCALE, height: heightMm * CANVAS_SCALE }}
+      style={{ width: widthMm * scale, height: heightMm * scale }}
       onPointerDown={() => onSelect(null)}
     >
       {elements.map((element) => (
         <ElementBox
           key={element.id}
           element={element}
+          scale={scale}
           selected={element.id === selectedId}
           onStartMove={(event) => startDrag(event, element, "move")}
           onStartResize={(event) => startDrag(event, element, "resize")}
@@ -110,16 +115,18 @@ export function LabelCanvas({
 
 function ElementBox({
   element,
+  scale,
   selected,
   onStartMove,
   onStartResize,
 }: {
   element: LabelElement;
+  scale: number;
   selected: boolean;
   onStartMove: (event: ReactPointerEvent) => void;
   onStartResize: (event: ReactPointerEvent) => void;
 }) {
-  const box = boxFor(element);
+  const box = boxFor(element, scale);
 
   return (
     <div
@@ -135,7 +142,7 @@ function ElementBox({
       }}
       onPointerDown={onStartMove}
     >
-      {renderContent(element)}
+      {renderContent(element, scale)}
       {selected ? (
         <div
           className="absolute right-0 bottom-0 size-3 translate-x-1/2 translate-y-1/2 cursor-nwse-resize rounded-full border-2 border-primary bg-background"
@@ -149,27 +156,30 @@ function ElementBox({
   );
 }
 
-function boxFor(element: LabelElement): {
+function boxFor(
+  element: LabelElement,
+  scale: number,
+): {
   left: number;
   top: number;
   width: number;
   height: number;
 } {
-  const left = element.x * CANVAS_SCALE;
-  const top = element.y * CANVAS_SCALE;
+  const left = element.x * scale;
+  const top = element.y * scale;
   if (element.type === "qrCode") {
-    return { left, top, width: element.size * CANVAS_SCALE, height: element.size * CANVAS_SCALE };
+    return { left, top, width: element.size * scale, height: element.size * scale };
   }
   if (element.type === "line") {
-    const thicknessPx = Math.max(2, element.thickness * PT_TO_MM * CANVAS_SCALE);
+    const thicknessPx = Math.max(2, element.thickness * PT_TO_MM * scale);
     return element.orientation === "horizontal"
-      ? { left, top: top - thicknessPx / 2, width: element.length * CANVAS_SCALE, height: thicknessPx }
-      : { left: left - thicknessPx / 2, top, width: thicknessPx, height: element.length * CANVAS_SCALE };
+      ? { left, top: top - thicknessPx / 2, width: element.length * scale, height: thicknessPx }
+      : { left: left - thicknessPx / 2, top, width: thicknessPx, height: element.length * scale };
   }
-  return { left, top, width: element.width * CANVAS_SCALE, height: element.height * CANVAS_SCALE };
+  return { left, top, width: element.width * scale, height: element.height * scale };
 }
 
-function renderContent(element: LabelElement) {
+function renderContent(element: LabelElement, scale: number) {
   switch (element.type) {
     case "text": {
       const display = element.placeholderKey
@@ -180,7 +190,7 @@ function renderContent(element: LabelElement) {
           className="size-full overflow-hidden whitespace-pre-wrap"
           style={{
             fontFamily: FONT_CSS[element.fontFamily],
-            fontSize: element.fontSize * PT_TO_MM * CANVAS_SCALE,
+            fontSize: element.fontSize * PT_TO_MM * scale,
             fontWeight: element.bold ? 700 : 400,
             fontStyle: element.italic ? "italic" : "normal",
             color: element.color,

ApiCore-Frontend/src/app/(app)/settings/label-templates/designer/label-designer.tsx

@@ -1,8 +1,17 @@
 "use client";
 
-import { ChangeEvent, useState } from "react";
+import { ChangeEvent, useEffect, useState } from "react";
 import { useRouter } from "next/navigation";
-import { Image as ImageIcon, Minus, QrCode, Type } from "lucide-react";
+import {
+  Download,
+  Image as ImageIcon,
+  Minus,
+  QrCode,
+  Type,
+  Upload,
+  ZoomIn,
+  ZoomOut,
+} from "lucide-react";
 import { toast } from "sonner";
 import {
   LabelElement,
@@ -25,6 +34,17 @@ import {
 import { LabelCanvas } from "./label-canvas";
 import { ElementPropertiesPanel } from "./element-properties-panel";
 
+const ELEMENT_TYPES = ["text", "qrCode", "image", "line"] as const;
+const ZOOM_STEPS: number[] = [0.5, 0.75, 1, 1.25, 1.5, 2];
+const ZOOM_MIN = ZOOM_STEPS[0];
+const ZOOM_MAX = ZOOM_STEPS[ZOOM_STEPS.length - 1];
+
+function nextZoomStep(current: number, direction: 1 | -1): number {
+  const index = ZOOM_STEPS.indexOf(current);
+  const nextIndex = Math.min(Math.max(index + direction, 0), ZOOM_STEPS.length - 1);
+  return ZOOM_STEPS[nextIndex];
+}
+
 function newId(): string {
   return crypto.randomUUID();
 }
@@ -57,6 +77,35 @@ export interface LabelDesignerValue {
   isDefault: boolean;
 }
 
+// Loose runtime check for imported JSON (own export, or hand/AI-authored) -
+// only verifies the shape is plausible enough to load into the canvas;
+// the backend's own DTO validation is still the real boundary check on save.
+function isLabelElementArray(value: unknown): value is LabelElement[] {
+  return (
+    Array.isArray(value) &&
+    value.every(
+      (item) =>
+        typeof item === "object" &&
+        item !== null &&
+        "id" in item &&
+        "type" in item &&
+        "x" in item &&
+        "y" in item &&
+        ELEMENT_TYPES.includes((item as { type: unknown }).type as (typeof ELEMENT_TYPES)[number]),
+    )
+  );
+}
+
+function slugify(name: string): string {
+  return (
+    name
+      .trim()
+      .toLowerCase()
+      .replace(/[^a-z0-9]+/g, "-")
+      .replace(/(^-|-$)/g, "") || "etikett"
+  );
+}
+
 interface LabelDesignerProps {
   initial?: LabelDesignerValue;
   onSubmit: (value: LabelDesignerValue) => Promise<void>;
@@ -72,6 +121,7 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
   const [elements, setElements] = useState<LabelElement[]>(initial?.elements ?? []);
   const [selectedId, setSelectedId] = useState<string | null>(null);
   const [isSubmitting, setIsSubmitting] = useState(false);
+  const [zoom, setZoom] = useState(1);
 
   const selectedElement = elements.find((element) => element.id === selectedId) ?? null;
 
@@ -88,12 +138,34 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
     );
   }
 
-  function deleteSelected() {
-    if (!selectedId) return;
-    setElements((current) => current.filter((element) => element.id !== selectedId));
-    setSelectedId(null);
+  function deleteElement(id: string) {
+    setElements((current) => current.filter((element) => element.id !== id));
+    setSelectedId((current) => (current === id ? null : current));
   }
 
+  function duplicateElement(id: string) {
+    const source = elements.find((element) => element.id === id);
+    if (!source) return;
+    const copy = { ...source, id: newId(), x: source.x + 4, y: source.y + 4 };
+    addElement(copy);
+  }
+
+  // Delete/Backspace removes the selected element, but never while the user
+  // is typing in a text field - only when focus is on the canvas itself.
+  useEffect(() => {
+    function onKeyDown(event: KeyboardEvent) {
+      if (event.key !== "Delete" && event.key !== "Backspace") return;
+      const target = event.target as HTMLElement | null;
+      if (target && ["INPUT", "TEXTAREA", "SELECT"].includes(target.tagName)) return;
+      if (selectedId) {
+        event.preventDefault();
+        deleteElement(selectedId);
+      }
+    }
+    window.addEventListener("keydown", onKeyDown);
+    return () => window.removeEventListener("keydown", onKeyDown);
+  }, [selectedId, elements]);
+
   function handlePlaceholderInsert(key: PlaceholderKey) {
     addElement(newTextElement({ placeholderKey: key, text: "" }));
   }
@@ -117,6 +189,48 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
     reader.readAsDataURL(file);
   }
 
+  function handleExport() {
+    const payload: LabelDesignerValue = { name, elements, widthMm, heightMm, isDefault };
+    const blob = new Blob([JSON.stringify(payload, null, 2)], { type: "application/json" });
+    const url = URL.createObjectURL(blob);
+    const link = document.createElement("a");
+    link.href = url;
+    link.download = `${slugify(name)}.json`;
+    link.click();
+    URL.revokeObjectURL(url);
+  }
+
+  function handleImportFile(event: ChangeEvent<HTMLInputElement>) {
+    const file = event.target.files?.[0];
+    event.target.value = "";
+    if (!file) return;
+    const reader = new FileReader();
+    reader.onload = () => {
+      try {
+        const parsed: unknown = JSON.parse(String(reader.result));
+        const importedElements = Array.isArray(parsed)
+          ? parsed
+          : (parsed as { elements?: unknown })?.elements;
+        if (!isLabelElementArray(importedElements)) {
+          toast.error("Datei enthält keine gültige Etikettenvorlage.");
+          return;
+        }
+        setElements(importedElements.map((element) => ({ ...element, id: newId() })));
+        if (!Array.isArray(parsed)) {
+          const value = parsed as Partial<LabelDesignerValue>;
+          if (typeof value.name === "string" && value.name && !name) setName(value.name);
+          if (typeof value.widthMm === "number") setWidthMm(value.widthMm);
+          if (typeof value.heightMm === "number") setHeightMm(value.heightMm);
+        }
+        setSelectedId(null);
+        toast.success("Vorlage importiert.");
+      } catch {
+        toast.error("Datei konnte nicht gelesen werden - ist es gültiges JSON?");
+      }
+    };
+    reader.readAsText(file);
+  }
+
   async function handleSubmit() {
     if (!name.trim()) {
       toast.error("Bitte einen Namen für die Vorlage angeben.");
@@ -185,8 +299,31 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
         </Card>
 
         <Card>
-          <CardHeader>
+          <CardHeader className="flex flex-row items-center justify-between gap-2">
             <CardTitle className="text-base">Elemente</CardTitle>
+            <div className="flex items-center gap-1">
+              <Button
+                type="button"
+                variant="ghost"
+                size="sm"
+                render={
+                  <label className="cursor-pointer">
+                    <Upload className="size-4" />
+                    Importieren
+                    <input
+                      type="file"
+                      accept="application/json"
+                      className="hidden"
+                      onChange={handleImportFile}
+                    />
+                  </label>
+                }
+              />
+              <Button type="button" variant="ghost" size="sm" onClick={handleExport}>
+                <Download className="size-4" />
+                Exportieren
+              </Button>
+            </div>
           </CardHeader>
           <CardContent className="flex flex-wrap items-center gap-2">
             <Button
@@ -251,12 +388,37 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
           </CardContent>
         </Card>
 
+        <div className="flex items-center gap-2">
+          <Button
+            type="button"
+            variant="outline"
+            size="icon-sm"
+            disabled={zoom <= ZOOM_MIN}
+            onClick={() => setZoom((current) => nextZoomStep(current, -1))}
+          >
+            <ZoomOut className="size-3.5" />
+          </Button>
+          <span className="w-12 text-center text-sm text-muted-foreground">
+            {Math.round(zoom * 100)}%
+          </span>
+          <Button
+            type="button"
+            variant="outline"
+            size="icon-sm"
+            disabled={zoom >= ZOOM_MAX}
+            onClick={() => setZoom((current) => nextZoomStep(current, 1))}
+          >
+            <ZoomIn className="size-3.5" />
+          </Button>
+        </div>
+
         <div className="overflow-auto rounded-lg bg-muted/30 p-6">
           <LabelCanvas
             widthMm={widthMm}
             heightMm={heightMm}
             elements={elements}
             selectedId={selectedId}
+            zoom={zoom}
             onSelect={setSelectedId}
             onChangeElement={changeElement}
           />
@@ -276,11 +438,13 @@ export function LabelDesigner({ initial, onSubmit, submitLabel }: LabelDesignerP
             <ElementPropertiesPanel
               element={selectedElement}
               onChange={(patch) => changeElement(selectedElement.id, patch)}
-              onDelete={deleteSelected}
+              onDelete={() => deleteElement(selectedElement.id)}
+              onDuplicate={() => duplicateElement(selectedElement.id)}
             />
           ) : (
             <p className="text-sm text-muted-foreground">
-              Element im Etikett anklicken, um es zu bearbeiten.
+              Element im Etikett anklicken, um es zu bearbeiten. Entf/Backspace löscht das
+              ausgewählte Element.
             </p>
           )}
         </CardContent>