v1.7.0: fix offer created_at override, invoice PDF translations, remove has_order filter

- Add created_at to offer create/update schemas so user-selected date is stored instead of always defaulting to now()
- Translate payment method in invoice PDF based on language (Příkazem → Bank transfer, etc.)
- Add order_date and cnb_rate translation keys, replace hardcoded inline strings
- Remove duplicate has_order filter from offers backend route

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/services/offers.service.ts

@@ -44,7 +44,6 @@ interface ListOffersParams {
   search: string;
   status?: string;
   customer_id?: number;
-  has_order?: string;
 }
 
 function enrichQuotation(q: any) {
@@ -73,24 +72,13 @@ function enrichQuotation(q: any) {
 }
 
 export async function listOffers(params: ListOffersParams) {
-  const {
-    page,
-    limit,
-    skip,
-    sort,
-    order,
-    search,
-    status,
-    customer_id,
-    has_order,
-  } = params;
+  const { page, limit, skip, sort, order, search, status, customer_id } =
+    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 (has_order === "yes") where.order_id = { not: null };
-  if (has_order === "no") where.order_id = null;
   if (search) {
     where.OR = [
       { quotation_number: { contains: search } },
@@ -189,6 +177,9 @@ export async function createOffer(body: Record<string, any>) {
         quotation_number: quotationNumber,
         project_code: body.project_code ? String(body.project_code) : null,
         customer_id: body.customer_id ? Number(body.customer_id) : null,
+        created_at: body.created_at
+          ? new Date(String(body.created_at))
+          : undefined,
         valid_until: body.valid_until
           ? new Date(String(body.valid_until))
           : null,
@@ -251,6 +242,12 @@ export async function updateOffer(id: number, body: Record<string, any>) {
   const data = {
     customer_id:
       body.customer_id !== undefined ? Number(body.customer_id) : undefined,
+    created_at:
+      body.created_at !== undefined
+        ? body.created_at
+          ? new Date(String(body.created_at))
+          : null
+        : undefined,
     valid_until:
       body.valid_until !== undefined
         ? body.valid_until