fix(print): send Windows plots to the chosen printer, name the default, report failures

On Windows a plot with no printer chosen went to the PDF application's
bare "print" verb — whatever that application considered its default —
and a viewer without a "printto" verb (Edge, store readers) silently
dropped the printer the dialog had chosen. The dialog also never named the
system default, and a failed printer enumeration left only "Default" and
"PDF" with the reason written to a console nobody sees.

- The default printer is looked up by name (GetDefaultPrinterW) both for
  the dialog's "System default printer (…)" entry and before every job.
- A pure route decision (plan_print_route) resolves "Default" to that
  name and uses the PDF application only when it registered a "printto"
  verb for .pdf (AssocQueryStringW); otherwise the job goes straight to
  the spooler through the existing GDI path. The report says which:
  "Sent to printer: NAME (direct print | via the PDF application)".
- list_printers reports the system's own error; the plot dialog shows it
  under the printer row and the command line warns once. A desktop without
  CUPS is an empty list, not an error.
- PRINTERS command: default printer, listed printers (or the error) and,
  on Windows, the print route — a report to paste into an issue.
- Properties… on the Default entry opens that printer's preferences sheet.
- GDI path: the driver's dmSize is kept (its private data lives behind
  it), the print raster is no longer memoised for the session, and a
  spooled temporary PDF is removed.

Tests: route planning (named / blank / no default / printto or not), the
PRINTERS command; the two Windows-only GDI tests pass the resolved name.

Co-Authored-By: Claude Opus 5 <[email protected]>

locales/ru-RU/opencadstudio.ftl

@@ -5100,6 +5100,15 @@ plot =
     .system-default-printer = Системный принтер по умолчанию
     .what-to-plot = Что спланировать
     .x-mm = X (мм)
+    .default-printer-name = Принтер по умолчанию: __ocs_fmt_0__
+    .default-printer-none-reported-by-the-system = Принтер по умолчанию: система не сообщает ни об одном
+    .printers-none-listed-by-the-system = Принтеры: система не перечисляет ни одного
+    .printers-count = Принтеры (__ocs_fmt_0__):
+    .could-not-list-printers-error = Не удалось получить список принтеров: __ocs_fmt_0__
+    .plots-go-through-the-pdf-application-command = Печать идёт через приложение PDF: __ocs_fmt_0__
+    .plots-go-straight-to-the-printer-no-pdf-application-registers-a-print-verb = Печать идёт напрямую на принтер (ни одно приложение PDF не регистрирует команду печати).
+    .via-the-pdf-application = через приложение PDF
+    .direct-print = прямая печать
     .y-mm = Y (мм)
 
 manage =