M4.78: File > Print opens the Print dialog and prints through the system

The Print dialog (Ctrl/Cmd+P) edits the document's print settings in the
sections General, Marks and Bleed, Output, Graphics, Color Management,
Advanced and Summary, with a preview of each printed page under the section
list (drag the art to move its placement). It drives print.setup,
print.preview and file.print; the preview pages now carry their transform,
printed area and trim box. Print sends the job's PDF to the chosen printer
through the new PrintService (lp on macOS/Linux, the shell print verb on
Windows, a hidden frame and the browser's print dialog on the web); without
one, or with PDF File, it saves the PDF. Done only keeps the settings.
UI commands file.print, print.printers and print.printerSetup.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/fileio/pdf.rs

@@ -239,7 +239,7 @@ fn export_pdf(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 /// `(path, value)` for every leaf of `v` that differs from `default` (`compression.color.ppi`).
-fn changed(prefix: &str, v: &Value, default: &Value, out: &mut Vec<Value>) {
+pub fn changed(prefix: &str, v: &Value, default: &Value, out: &mut Vec<Value>) {
     match (v, default) {
         (Value::Object(o), Value::Object(d)) => {
             for (k, x) in o {