M10: Windows printing prints at actual size, off the UI thread (follow-up to #847) (#1007)

* M10: Windows printing prints at actual size, off the UI thread (follow-up to #847)

- Sheets print at 100% on the driver's paper closest to their size, landscape
  when wide, instead of being shrunk into .NET's default 1-inch margins
  (about 76% on Letter) and never rotated. Each sheet is capped at ~64 MP so a
  poster-sized sheet can't exhaust memory.
- PowerShell runs with CREATE_NO_WINDOW: the release app has no console, so
  Windows opened one over the app for the whole job.
- The Print dialog lists printers in the background (the desktop app's
  printer_source) and spools jobs on a worker thread, so Ctrl+P and long jobs
  no longer freeze the UI. A list arriving late preselects the default only if
  the user hasn't picked a printer.
- Parity evidence named a test that #847 renamed; xtask parity passes again.
  The raster-only limit is now stated in the parity notes and README.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

* M10: refresh catalog hashes in ATTRIBUTION.toml for the new print strings

Co-Authored-By: Claude Opus 5.5 <[email protected]>

---------

Co-authored-by: Claude Opus 5.5 <[email protected]>

apps/pdfcraft/src/main.rs

@@ -305,6 +305,7 @@ fn app_creator<'a>(
         app.integrated_titlebar = integrated;
         app.system_text_scale = text_scale::system();
         app.update_source = Some(std::sync::Arc::new(updates::latest_release));
+        app.printer_source = Some(pdfcraft_ui_egui::system_printers());
         app.os_key_store_ids = cfg!(any(target_os = "macos", target_os = "windows"));
         #[cfg(target_os = "macos")]
         {