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/routes/admin/offers-pdf.ts

@@ -203,9 +203,11 @@ const TRANSLATIONS: Record<string, Record<string, string>> = {
   unit_price: { EN: "Unit Price", CZ: "Jedn. cena" },
   included: { EN: "Included", CZ: "Zahrnuto" },
   total: { EN: "Total", CZ: "Celkem" },
-  subtotal: { EN: "Subtotal", CZ: "Mezisou\u010Det" },
-  vat: { EN: "VAT", CZ: "DPH" },
-  total_to_pay: { EN: "Total to pay", CZ: "Celkem k \u00FAhrad\u011B" },
+  total_no_vat: { EN: "Total excl. VAT", CZ: "Celkem bez DPH" },
+  vat_notice: {
+    EN: "Prices are exclusive of VAT. VAT will be charged according to applicable regulations.",
+    CZ: "Ceny jsou uvedeny bez DPH. DPH bude \u00FA\u010Dtov\u00E1no dle platn\u00FDch p\u0159edpis\u016F.",
+  },
   ico: { EN: "ID", CZ: "I\u010CO" },
   dic: { EN: "VAT ID", CZ: "DI\u010C" },
   page: { EN: "Page", CZ: "Strana" },
@@ -256,18 +258,15 @@ export default async function offersPdfRoutes(
           logoImg = `<img src="data:${escapeHtml(mime)};base64,${buf.toString("base64")}" class="logo" />`;
         }
 
+        // Offers are NOT tax documents — the total is NET only (no VAT math).
         const items = quotation.quotation_items;
-        let subtotal = 0;
+        let total = 0;
         for (const item of items) {
           if (item.is_included_in_total !== false) {
-            subtotal +=
+            total +=
               (Number(item.quantity) || 0) * (Number(item.unit_price) || 0);
           }
         }
-        const applyVat = !!quotation.apply_vat;
-        const vatRate = Number(quotation.vat_rate) || 21;
-        const vatAmount = applyVat ? subtotal * (vatRate / 100) : 0;
-        const totalToPay = subtotal + vatAmount;
         let hasScopeContent = false;
         for (const s of quotation.scope_sections) {
           if ((s.content || "").trim() || (s.title || "").trim()) {
@@ -318,23 +317,12 @@ export default async function offersPdfRoutes(
           </tr>`;
         });
 
-        let totalsHtml = "";
-        if (applyVat) {
-          totalsHtml += `<div class="detail-rows">
-          <div class="row">
-            <span class="label">${escapeHtml(t("subtotal"))}:</span>
-            <span class="value">${formatCurrency(subtotal, currency)}</span>
-          </div>
-          <div class="row">
-            <span class="label">${escapeHtml(t("vat"))} (${Math.round(vatRate)}%):</span>
-            <span class="value">${formatCurrency(vatAmount, currency)}</span>
-          </div>
-        </div>`;
-        }
-        totalsHtml += `<div class="grand">
-      <span class="label">${escapeHtml(t("total_to_pay"))}</span>
-      <span class="value">${formatCurrency(totalToPay, currency)}</span>
-    </div>`;
+        // No Mezisoučet/VAT rows — they would only duplicate the net total.
+        const totalsHtml = `<div class="grand">
+      <span class="label">${escapeHtml(t("total_no_vat"))}</span>
+      <span class="value">${formatCurrency(total, currency)}</span>
+    </div>
+    <div class="vat-note">${escapeHtml(t("vat_notice"))}</div>`;
         const quotationNumber = escapeHtml(quotation.quotation_number);
 
         let scopeHtml = "";
@@ -578,6 +566,12 @@ ${indentCSS}
     border-bottom: 2.5pt solid #de3a3a;
     padding-bottom: 1mm;
   }
+  .totals .vat-note {
+    text-align: right;
+    font-size: 8pt;
+    color: #646464;
+    margin-top: 2mm;
+  }
 
   /* ---- Scope sections ---- */
   .scope-page {