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/services/offers.service.ts

@@ -37,15 +37,44 @@ const ALLOWED_SORT_FIELDS = [
   "status",
 ];
 
-interface ListOffersParams {
+interface OfferFilterParams {
+  search?: string;
+  status?: string;
+  customer_id?: number;
+}
+
+interface ListOffersParams extends OfferFilterParams {
   page: number;
   limit: number;
   skip: number;
   sort: string;
   order: "asc" | "desc";
   search: string;
-  status?: string;
-  customer_id?: number;
+}
+
+export interface CurrencyAmount {
+  amount: number;
+  currency: string;
+}
+
+/**
+ * Shared `where` builder for the offers list and the per-currency stats
+ * aggregation, so both stay in sync (any new filter applies to both). Offers
+ * have NO month/year filter — the list filters by search + status + customer_id.
+ */
+function buildOfferWhere(params: OfferFilterParams): Record<string, unknown> {
+  const { search, status, customer_id } = params;
+  const where: Record<string, unknown> = {};
+  if (status) where.status = status;
+  if (customer_id) where.customer_id = customer_id;
+  if (search) {
+    where.OR = [
+      { quotation_number: { contains: search } },
+      { project_code: { contains: search } },
+      { customers: { name: { contains: search } } },
+    ];
+  }
+  return where;
 }
 
 function enrichQuotation(q: any) {
@@ -74,20 +103,10 @@ function enrichQuotation(q: any) {
 }
 
 export async function listOffers(params: ListOffersParams) {
-  const { page, limit, skip, sort, order, search, status, customer_id } =
-    params;
+  const { page, limit, skip, sort, order } = params;
   const sortField = ALLOWED_SORT_FIELDS.includes(sort) ? sort : "id";
 
-  const where: Record<string, unknown> = {};
-  if (status) where.status = status;
-  if (customer_id) where.customer_id = customer_id;
-  if (search) {
-    where.OR = [
-      { quotation_number: { contains: search } },
-      { project_code: { contains: search } },
-      { customers: { name: { contains: search } } },
-    ];
-  }
+  const where = buildOfferWhere(params);
 
   const [quotations, total] = await Promise.all([
     prisma.quotations.findMany({
@@ -128,6 +147,43 @@ export async function listOffers(params: ListOffersParams) {
   return { data: enriched, total, page, limit };
 }
 
+/**
+ * Sum offer TOTAL (incl. VAT) per currency across the WHOLE filtered set (not a
+ * single page). Reuses `buildOfferWhere` so the filters track the list, and
+ * `enrichQuotation` so the per-offer math matches the list/detail exactly.
+ * Returns one entry per currency, rounded to 2dp, zero/empty totals dropped.
+ */
+export async function getOfferTotals(
+  params: OfferFilterParams,
+): Promise<{ totals: CurrencyAmount[] }> {
+  const where = buildOfferWhere(params);
+
+  const quotations = await prisma.quotations.findMany({
+    where,
+    include: {
+      customers: { select: { id: true, name: true } },
+      quotation_items: { orderBy: { position: "asc" } },
+      scope_sections: { orderBy: { position: "asc" } },
+    },
+  });
+
+  const byCurrency: Record<string, number> = {};
+  for (const q of quotations) {
+    const { total, currency } = enrichQuotation(q);
+    const cur = currency || "CZK";
+    byCurrency[cur] = (byCurrency[cur] || 0) + (Number(total) || 0);
+  }
+
+  const totals: CurrencyAmount[] = Object.entries(byCurrency)
+    .map(([currency, amount]) => ({
+      currency,
+      amount: Math.round(amount * 100) / 100,
+    }))
+    .filter((t) => t.amount > 0);
+
+  return { totals };
+}
+
 export async function getOffer(id: number) {
   const quotation = await prisma.quotations.findUnique({
     where: { id },