feat(offers,invoices): per-currency 'Celkem' totals beneath the lists (consistent with orders)

Mirrors the orders totals exactly: /stats (offers) + /list-totals (issued +
received invoices) endpoints sum each doc's total per currency across the active
filter (reusing extracted where-builders so they stay in sync with the lists),
rendered as the identical 'Celkem: …' block via the shared formatMultiCurrency.
Existing invoice/received KPI stats untouched.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/routes/admin/invoices.ts

@@ -12,6 +12,7 @@ import {
 import {
   markOverdueInvoices,
   listInvoices,
+  getInvoiceListTotals,
   getNextInvoiceNumberFormatted,
   getNextInvoiceNumberPreview,
   getInvoiceStats,
@@ -77,7 +78,7 @@ export default async function invoicesRoutes(
     },
   );
 
-  // GET /api/admin/invoices/stats
+  // GET /api/admin/invoices/stats — monthly KPI cards (paid/awaiting/overdue/VAT).
   fastify.get(
     "/stats",
     { preHandler: requirePermission("invoices.view") },
@@ -90,6 +91,27 @@ export default async function invoicesRoutes(
     },
   );
 
+  // GET /api/admin/invoices/list-totals — per-currency total (incl. VAT) summed
+  // over the WHOLE filtered set (not one page), matching the issued-invoice
+  // list's filters (search/status/month/year). Distinct path from "/stats" (the
+  // KPI cards) to avoid colliding with that endpoint. Registered BEFORE "/:id"
+  // so the literal path isn't captured as an invoice id.
+  fastify.get(
+    "/list-totals",
+    { preHandler: requirePermission("invoices.view") },
+    async (request, reply) => {
+      const query = request.query as Record<string, unknown>;
+      const result = await getInvoiceListTotals({
+        search: query.search ? String(query.search) : undefined,
+        status: query.status ? String(query.status) : undefined,
+        customer_id: query.customer_id ? Number(query.customer_id) : undefined,
+        month: query.month ? Number(query.month) : undefined,
+        year: query.year ? Number(query.year) : undefined,
+      });
+      return success(reply, { totals: result.totals });
+    },
+  );
+
   // GET /api/admin/invoices/order-data/:id
   fastify.get<{ Params: { id: string } }>(
     "/order-data/:id",