feat(vat)!: remove VAT entirely from offers, orders and issued orders

Accounting rule: nabidky, objednavky (incl. confirmation PDF) and objednavky
vydane are NOT tax documents - VAT belongs only on invoices. Per user
decision this is a FULL removal including DB columns.

- migration: DROP orders.vat_rate/apply_vat, issued_orders.vat_rate/apply_vat,
  issued_order_items.vat_rate, quotations.vat_rate/apply_vat (applied to
  dev + test DBs)
- services: net-only totals everywhere (computeIssuedOrderTotals(items) ->
  {total}; enrichOrder/enrichQuotation net; per-currency list totals net)
- PDFs (offers, order confirmation, issued order): no VAT columns/summary,
  single 'Celkem bez DPH' / 'Total excl. VAT' total, note under totals:
  'Ceny jsou uvedeny bez DPH. DPH bude uctovano dle platnych predpisu.';
  duplicate Cena/Celkem column merged (desc width 56%); orders-pdf render
  extracted as exported renderOrderConfirmationHtml for testability
- frontend: Uplatnit DPH checkboxes, VAT selects and per-item VAT columns
  removed from OfferDetail/OrderDetail/IssuedOrderDetail/
  OrderConfirmationModal/ReceivedOrders manual-create; list footers read
  'Celkem bez DPH'; invoice-from-order prefill now takes the company default
  VAT (invoice decides its own VAT)
- tests: suites reworked to net math; new pdf-vat-note.test.ts pins the
  exact cs+en note text and VAT-free layout on all three PDFs

Invoices and received invoices keep their VAT handling unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/services/issued-orders.service.ts

@@ -14,7 +14,6 @@ export interface IssuedOrderItemInput {
   quantity?: number | string | null;
   unit?: string | null;
   unit_price?: number | string | null;
-  vat_rate?: number | string | null;
   position?: number | null;
 }
 
@@ -23,8 +22,6 @@ export interface IssuedOrderInput {
   supplier_id?: number | string | null;
   status?: string;
   currency?: string;
-  vat_rate?: number | string | null;
-  apply_vat?: boolean | number | string;
   exchange_rate?: number | string | null;
   order_date?: string | null;
   delivery_date?: string | null;
@@ -106,32 +103,18 @@ const ALLOWED_SORT_FIELDS = [
   "currency",
 ];
 
-/** NET base + VAT-on-top, rounded per line before accumulation (mirrors invoices). */
+/**
+ * NET-only total: issued orders (PO) are not tax documents — VAT never appears
+ * on them. The total is the plain sum of qty × unit_price, rounded to 2dp.
+ */
 export function computeIssuedOrderTotals(
-  items: Array<{ quantity: unknown; unit_price: unknown; vat_rate: unknown }>,
-  applyVat: boolean | null,
-  defaultVatRate: unknown,
+  items: Array<{ quantity: unknown; unit_price: unknown }>,
 ) {
-  let subtotal = 0;
-  let vat = 0;
+  let total = 0;
   for (const it of items) {
-    const base = (Number(it.quantity) || 0) * (Number(it.unit_price) || 0);
-    subtotal += base;
-    if (applyVat) {
-      const rate =
-        it.vat_rate != null && it.vat_rate !== ""
-          ? Number(it.vat_rate)
-          : defaultVatRate != null
-            ? Number(defaultVatRate)
-            : 21;
-      vat += Math.round(base * (rate / 100) * 100) / 100;
-    }
+    total += (Number(it.quantity) || 0) * (Number(it.unit_price) || 0);
   }
-  return {
-    subtotal: Math.round(subtotal * 100) / 100,
-    vat_amount: Math.round(vat * 100) / 100,
-    total: Math.round((subtotal + vat) * 100) / 100,
-  };
+  return { total: Math.round(total * 100) / 100 };
 }
 
 export async function listIssuedOrders(params: ListIssuedOrdersParams) {
@@ -163,11 +146,7 @@ export async function listIssuedOrders(params: ListIssuedOrdersParams) {
   ]);
 
   const enriched = rows.map((o) => {
-    const totals = computeIssuedOrderTotals(
-      o.issued_order_items,
-      o.apply_vat,
-      o.vat_rate,
-    );
+    const totals = computeIssuedOrderTotals(o.issued_order_items);
     const { issued_order_items, ...rest } = o;
     return {
       ...rest,
@@ -181,7 +160,7 @@ export async function listIssuedOrders(params: ListIssuedOrdersParams) {
 }
 
 /**
- * Sum issued-order TOTAL (incl. VAT) per currency across the WHOLE filtered set
+ * Sum issued-order NET total per currency across the WHOLE filtered set
  * (not a single page). Reuses `buildIssuedOrderWhere` so filters track the list,
  * and `computeIssuedOrderTotals` so per-order math matches the list/detail.
  * Currency defaults to "CZK" when the column is null. Returns one entry per
@@ -199,11 +178,7 @@ export async function getIssuedOrderTotals(
 
   const byCurrency: Record<string, number> = {};
   for (const o of rows) {
-    const { total } = computeIssuedOrderTotals(
-      o.issued_order_items,
-      o.apply_vat,
-      o.vat_rate,
-    );
+    const { total } = computeIssuedOrderTotals(o.issued_order_items);
     const cur = o.currency || "CZK";
     byCurrency[cur] = (byCurrency[cur] || 0) + (Number(total) || 0);
   }
@@ -286,8 +261,6 @@ export async function createIssuedOrder(body: IssuedOrderInput) {
         supplier_id: supplierId,
         status: status as $Enums.issued_orders_status,
         currency: body.currency ? String(body.currency) : "CZK",
-        vat_rate: body.vat_rate != null ? Number(body.vat_rate) : 21.0,
-        apply_vat: body.apply_vat !== false,
         exchange_rate:
           body.exchange_rate != null ? Number(body.exchange_rate) : 1.0,
         // order_date is @db.Date (truncated to the UTC date part) — the
@@ -322,7 +295,6 @@ export async function createIssuedOrder(body: IssuedOrderInput) {
           quantity: item.quantity ?? 1,
           unit: item.unit ?? null,
           unit_price: item.unit_price ?? 0,
-          vat_rate: item.vat_rate ?? 21.0,
           position: item.position ?? i,
         })),
       });
@@ -373,12 +345,6 @@ export async function updateIssuedOrder(id: number, body: IssuedOrderInput) {
       }
       data.supplier_id = supplierId;
     }
-    if (body.vat_rate !== undefined) data.vat_rate = Number(body.vat_rate);
-    if (body.apply_vat !== undefined)
-      data.apply_vat =
-        body.apply_vat === true ||
-        body.apply_vat === 1 ||
-        body.apply_vat === "1";
     if (body.exchange_rate !== undefined)
       data.exchange_rate =
         body.exchange_rate != null ? Number(body.exchange_rate) : null;
@@ -431,7 +397,6 @@ export async function updateIssuedOrder(id: number, body: IssuedOrderInput) {
           quantity: item.quantity ?? 1,
           unit: item.unit ?? null,
           unit_price: item.unit_price ?? 0,
-          vat_rate: item.vat_rate ?? 21.0,
           position: item.position ?? i,
         })),
       });