feat: Remove 'Beträge' section from invoice template

Remove all invoice totals elements:
- invoice-subtotal (Zwischensumme)
- invoice-tax (Mehrwertsteuer)
- invoice-total (Gesamtbetrag)

Remove 'Beträge' category from palette groups.
Adjust positions of remaining elements (payment-terms, bank-details).

frontend/src/pages/InvoiceTemplatePage.tsx

@@ -42,9 +42,7 @@ const INVOICE_LOCKED_TEXT_PALETTE_IDS = new Set([
   "customer-city",
   "customer-email",
   "customer-phone",
-  "invoice-subtotal",
+
-  "invoice-tax",
-  "invoice-total",
 
   "payment-terms",
   "bank-details",
@@ -363,39 +361,6 @@ const INVOICE_PALETTE_ITEMS: PaletteItem[] = [
     defaultContent: (user) =>
       `Tel.: ${user?.phoneNumber ?? ""}\nE-Mail: ${user?.email ?? ""}`,
   },
-  {
-    id: "invoice-subtotal",
-    category: "invoice-totals",
-    label: "Zwischensumme",
-    description: "Nettobetrag",
-    width: 200,
-    fontSize: 16,
-    fontWeight: 600,
-    textAlign: "right",
-    defaultContent: () => "Zwischensumme: 95,00 €",
-  },
-  {
-    id: "invoice-tax",
-    category: "invoice-totals",
-    label: "Mehrwertsteuer",
-    description: "MwSt-Betrag",
-    width: 200,
-    fontSize: 16,
-    fontWeight: 400,
-    textAlign: "right",
-    defaultContent: () => "MwSt. (19%): 18,05 €",
-  },
-  {
-    id: "invoice-total",
-    category: "invoice-totals",
-    label: "Gesamtbetrag",
-    description: "Bruttobetrag",
-    width: 200,
-    fontSize: 20,
-    fontWeight: 700,
-    textAlign: "right",
-    defaultContent: () => "Gesamt: 113,05 €",
-  },
   {
     id: "payment-terms",
     category: "invoice-footer",
@@ -463,7 +428,7 @@ const INVOICE_PALETTE_GROUPS: Array<{ category: PaletteCategory; title: string }
   { category: "invoice-header", title: "Rechnungskopf" },
   { category: "customer-data", title: "Kundendaten" },
   { category: "issuer-data", title: "Aussteller" },
-  { category: "invoice-totals", title: "Beträge" },
+
   { category: "invoice-footer", title: "Fußbereich" },
   { category: "free-elements", title: "Freie Elemente" },
 ];
@@ -1001,12 +966,9 @@ function createInvoiceStarterLayout(user: UserOption | null, paletteItems: Palet
     createElementFromPalette(requirePaletteItem(paletteItems, "customer-city"), user, { x: 140, y: 270 }),
     createElementFromPalette(requirePaletteItem(paletteItems, "customer-number"), user, { x: 56, y: 290 }),
     horizontalLine(56, 330, 646),
-    createElementFromPalette(requirePaletteItem(paletteItems, "invoice-subtotal"), user, { x: 500, y: 460 }),
-    createElementFromPalette(requirePaletteItem(paletteItems, "invoice-tax"), user, { x: 500, y: 486 }),
-    createElementFromPalette(requirePaletteItem(paletteItems, "invoice-total"), user, { x: 500, y: 520 }),
     horizontalLine(56, 560, 646),
-    createElementFromPalette(requirePaletteItem(paletteItems, "payment-terms"), user, { x: 56, y: 580 }),
+    createElementFromPalette(requirePaletteItem(paletteItems, "payment-terms"), user, { x: 56, y: 360 }),
-    createElementFromPalette(requirePaletteItem(paletteItems, "bank-details"), user, { x: 56, y: 620 }),
+    createElementFromPalette(requirePaletteItem(paletteItems, "bank-details"), user, { x: 56, y: 400 }),
   ];
 }