feat(scanner): Mobile Scanner App mit echten Produktionsaufträgen

Scanner-App  Tauri v2 Android App mit
Login, Barcode-Scanner, Consume/Move/Book-Flows und Aufgabenliste.

TasksPage lädt echte RELEASED/IN_PROGRESS Produktionsaufträge via API,
Consume-Flow nutzt den konkreten Auftrag für korrekte Rezept-Skalierung
statt blind den ersten IN_PROGRESS-Auftrag zu nehmen.

Backend: FindStockByBatchId Use Case + REST-Endpoint für Stock-Lookup
per Chargennummer.

frontend/apps/scanner/src/pages/ConsumeFlowPage.tsx

@@ -0,0 +1,119 @@
+import { FlaskConical, ScanLine, Check, PackageSearch } from 'lucide-react';
+import { Card, Button } from '@effigenix/ui';
+import { PageActions } from '../components/PageActions';
+import { PageHeader } from '../components/PageHeader';
+import { StepIndicator } from '../components/StepIndicator';
+import { useNavigation } from '../navigation';
+import { useFlowState } from '../flow-state';
+
+export function ConsumeFlowPage() {
+  const { navigate, setFlowType } = useNavigation();
+  const { consumeItems, productionOrder } = useFlowState();
+  const hasItems = consumeItems.length > 0;
+
+  if (!productionOrder) {
+    navigate('tasks');
+    return null;
+  }
+
+  function startScan() {
+    setFlowType('consume');
+    navigate('scan');
+  }
+
+  return (
+    <div className="flex-1 flex flex-col animate-fade-in">
+      <PageHeader
+        title="Verbrauch erfassen"
+        subtitle={
+          <span>
+            Produktionscharge:{' '}
+            <span className="font-mono font-medium text-brand-600">{productionOrder.batchNumber ?? '–'}</span>
+          </span>
+        }
+      />
+
+      <StepIndicator
+        steps={[
+          { label: 'Prod.-Charge', state: 'done' },
+          { label: 'Materialien', state: hasItems ? 'done' : 'active' },
+          { label: 'Bestätigen', state: hasItems ? 'active' : 'pending' },
+        ]}
+      />
+
+      {/* Production batch */}
+      <div className="px-5 mb-2">
+        <Card className="p-2.5 flex items-center gap-3 border-brand-200 bg-brand-50">
+          <div className="w-8 h-8 rounded-lg bg-brand-100 flex items-center justify-center">
+            <FlaskConical className="w-4 h-4 text-brand-600" />
+          </div>
+          <div className="flex-1 min-w-0">
+            <div className="text-sm font-semibold text-warm-800">
+              {productionOrder.batchNumber ?? '–'} · {productionOrder.articleName}
+            </div>
+            <div className="text-xs text-warm-500">
+              Soll: {productionOrder.plannedQuantity} {productionOrder.plannedQuantityUnit} · In Produktion
+            </div>
+          </div>
+        </Card>
+      </div>
+
+      {/* Scanned materials – scrollable area */}
+      <div className="px-5 flex-1 min-h-0 overflow-y-auto space-y-2">
+        <h2 className="text-xs font-bold text-warm-500 uppercase tracking-wider mb-2">
+          Gescannte Materialien ({consumeItems.length})
+        </h2>
+
+        {consumeItems.length > 0 ? (
+          <div className="space-y-2">
+            {consumeItems.map((item, i) => (
+              <Card key={i} className="p-2.5 flex items-center gap-3 animate-fade-in">
+                <div className="w-2 h-10 rounded-full bg-brand-400 shrink-0" />
+                <div className="flex-1 min-w-0">
+                  <div className="text-sm font-medium text-warm-800">{item.name}</div>
+                  <div className="text-xs text-warm-500">
+                    {item.batch} · {item.location}
+                  </div>
+                </div>
+                <div className="text-right shrink-0">
+                  <div className="font-mono font-semibold text-sm text-warm-800">
+                    {item.quantity} {item.unit}
+                  </div>
+                  {item.required != null && (
+                    <div className="text-2xs text-warm-400">
+                      von {item.required} {item.requiredUnit ?? item.unit}
+                    </div>
+                  )}
+                </div>
+              </Card>
+
+            ))}
+          </div>
+        ) : (
+          <Card className="p-5 text-center">
+            <div className="inline-flex items-center justify-center w-11 h-11 rounded-xl bg-warm-100 mb-2">
+              <PackageSearch className="w-5 h-5 text-warm-400" />
+            </div>
+            <p className="text-sm text-warm-500 mb-0.5">Noch keine Materialien erfasst</p>
+            <p className="text-xs text-warm-400">
+              Chargen-Etiketten der Eingangsmaterialien scannen.
+            </p>
+          </Card>
+        )}
+        <Button variant="secondary" size='lg' className="w-full" onClick={startScan}>
+          <ScanLine className="w-4 h-4" />
+          {consumeItems.length === 0 ? 'Erste Zutat scannen' : 'Nächste Zutat scannen'}
+        </Button>
+      </div>
+
+      <PageActions>
+        {hasItems && (
+          <Button variant="primary" size='lg' className="w-full" onClick={() => navigate('consume-confirm')}>
+            <Check className="w-5 h-5" />
+            {consumeItems.length} Verbrauch{consumeItems.length !== 1 ? 'e' : ''} buchen
+          </Button>
+        )}
+      </PageActions>
+    </div>
+  );
+}