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/orders.service.ts

@@ -72,23 +72,20 @@ async function syncProjectStatus(
   });
 }
 
-// ⚠ Also called by getOrderTotals with a MINIMAL select (currency, apply_vat,
-// vat_rate, item quantity/unit_price/is_included_in_total). If you read a NEW
-// order/item field here, add it to that select — a field missing from the
-// select is silently 0 in the per-currency totals.
+// ⚠ Also called by getOrderTotals with a MINIMAL select (currency, item
+// quantity/unit_price/is_included_in_total). If you read a NEW order/item
+// field here, add it to that select — a field missing from the select is
+// silently 0 in the per-currency totals.
+//
+// Orders are NOT tax documents — totals are NET only (no VAT anywhere).
 function enrichOrder(o: any) {
-  const subtotal = o.order_items
+  const total = o.order_items
     .filter((i: any) => i.is_included_in_total !== false)
     .reduce(
       (s: number, i: any) =>
         s + (Number(i.quantity) || 0) * (Number(i.unit_price) || 0),
       0,
     );
-  const vatAmount = o.apply_vat
-    ? subtotal *
-      ((o.vat_rate != null && o.vat_rate !== "" ? Number(o.vat_rate) : 21) /
-        100)
-    : 0;
   const { order_items, order_sections, ...rest } = o;
   const invoice = o.invoices?.[0] || null;
   return {
@@ -100,9 +97,7 @@ function enrichOrder(o: any) {
     project_code: o.quotations?.project_code || null,
     invoice_id: invoice?.id || null,
     invoice_number: invoice?.invoice_number || null,
-    subtotal: Math.round(subtotal * 100) / 100,
-    vat_amount: Math.round(vatAmount * 100) / 100,
-    total: Math.round((subtotal + vatAmount) * 100) / 100,
+    total: Math.round(total * 100) / 100,
   };
 }
 
@@ -192,7 +187,7 @@ export interface CurrencyAmount {
 }
 
 /**
- * Sum order TOTAL (incl. VAT) per currency across the WHOLE filtered set (not a
+ * Sum order NET total per currency across the WHOLE filtered set (not a
  * single page). Reuses `buildOrderWhere` so the filters track the list, and
  * `enrichOrder` so the per-order math matches the list/detail exactly. Returns
  * one entry per currency, rounded to 2dp, zero/empty totals dropped.
@@ -202,15 +197,13 @@ export async function getOrderTotals(
 ): Promise<{ totals: CurrencyAmount[] }> {
   const where = buildOrderWhere(params);
 
-  // Select ONLY what the math needs (currency + VAT flags + item numbers).
+  // Select ONLY what the math needs (currency + item numbers).
   // This runs over the WHOLE filtered set, so pulling attachment blobs,
   // sections HTML or relations here would multiply the query size for nothing.
   const orders = await prisma.orders.findMany({
     where,
     select: {
       currency: true,
-      apply_vat: true,
-      vat_rate: true,
       order_items: {
         select: {
           quantity: true,
@@ -335,8 +328,6 @@ export async function createOrderFromQuotation(
         status: "prijata",
         currency: quotation.currency || "CZK",
         language: quotation.language || "cs",
-        vat_rate: quotation.vat_rate ?? 21.0,
-        apply_vat: quotation.apply_vat ?? true,
         scope_title: quotation.scope_title,
         scope_description: quotation.scope_description,
         attachment_data: attachmentBuffer
@@ -428,8 +419,6 @@ interface CreateOrderData {
   status: string;
   currency: string;
   language: string;
-  vat_rate: number;
-  apply_vat?: boolean;
   exchange_rate?: number;
   scope_title?: string | null;
   scope_description?: string | null;
@@ -469,8 +458,6 @@ export async function createOrder(
           status: body.status,
           currency: body.currency,
           language: body.language,
-          vat_rate: body.vat_rate,
-          apply_vat: body.apply_vat !== false,
           exchange_rate: body.exchange_rate,
           scope_title: body.scope_title ?? null,
           scope_description: body.scope_description ?? null,
@@ -629,10 +616,6 @@ export async function updateOrder(id: number, body: UpdateOrderData) {
   }
   if (body.customer_id !== undefined)
     data.customer_id = body.customer_id ? Number(body.customer_id) : null;
-  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 (Array.isArray(body.items) || Array.isArray(body.sections)) {
     if (currentStatus !== "prijata" && currentStatus !== "v_realizaci") {