feat(delivery): add supplier article lookup, article creation, and unified parsing

- Unified PDF/TXT parsing to single POST /api/delivery/parse endpoint
- Added supplier article lookup with SKU/EAN matching in delivery lines
- Added "Artikel anlegen" button to create articles from missing SKUs
- Fixed delivery line taxrate field (was sending 'tax', now 'taxrate')
- Extended TXT file support for rescan functionality
- Updated ApiClient with getArticles method for supplier article lookup
- Added supplier article state management to deliveryEditorAutomat

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

src/components/manifest/manifestConfig.js

@@ -114,9 +114,9 @@ export function buildLines(lines, { requireAtLeastOne }) {
       !sku && !name && amount == null && net == null && tax == null && rebate == null;
     if (blank) continue;
     if ((!sku && !name) || amount == null || net == null || tax == null) {
-      throw new Error('Jede Zeile braucht SKU oder Name, Amount, Net und Tax.');
+      throw new Error('Jede Zeile braucht SKU oder Name, Amount, Net und Taxrate.');
     }
-    const row = { amount, net, tax };
+    const row = { amount, net, taxrate: tax };
     if (sku) row.sku = sku;
     if (name) row.name = name;
     if (rebate != null) row.rebate = rebate;