M3.9: swatches in colour groups are first-class — Document Color Mode converts them, they can be spot colours with their own plate and PDF Separation, and Document Info counts them

Document::swatches_iter/_mut, swatch_mut, swatch_group_of, remove_swatch and a copy-on-write
walk over linked solid paints (map_solid_paints) cover every colour group.

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

crates/engine/src/cmd/colormgmt.rs

@@ -257,7 +257,7 @@ fn convert_mode(s: &mut Session, p: &Value) -> Result<Value> {
             }
             n
         });
-        for sw in &mut d.swatches {
+        for sw in d.swatches_iter_mut() {
             match &mut sw.paint {
                 Paint::Solid { color, .. } => *color = conv(color),
                 Paint::Gradient(g) => {
@@ -486,14 +486,14 @@ fn set_spot(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "swatch.setSpot";
     let name = str_param(p, "name").ok_or_else(|| bad(C, "missing `name`"))?.to_string();
     let spot = bool_or(p, "spot", true);
-    let sw = s.doc()?.doc.swatches.iter().find(|w| w.name == name).ok_or_else(|| bad(C, format!("no swatch `{name}`")))?;
+    let sw = s.doc()?.doc.swatch(&name).ok_or_else(|| bad(C, format!("no swatch `{name}`")))?;
     if !matches!(sw.paint, Paint::Solid { .. }) {
         return Err(bad(C, "only solid-colour swatches can be spot colours"));
     }
     if sw.spot != spot {
         let n = name.clone();
         s.edit("Swatch Options", |d, _| {
-            if let Some(w) = d.swatches.iter_mut().find(|w| w.name == n) {
+            if let Some(w) = d.swatch_mut(&n) {
                 w.spot = spot;
                 if spot {
                     w.global = true;

crates/engine/src/cmd/docinfo.rs

@@ -113,7 +113,7 @@ fn info(s: &mut Session, p: &Value) -> Result<Value> {
         "images": images,
         "symbols": symbols,
         "spotColors": spot,
-        "swatches": d.swatches.len(),
+        "swatches": d.swatches_iter().count(),
         "graphicStyles": d.graphic_styles.len(),
         "characterStyles": d.char_styles.len(),
         "paragraphStyles": d.para_styles.len(),

crates/engine/src/cmd/docmenu.rs

@@ -469,7 +469,7 @@ fn color_mode(s: &mut Session, p: &Value) -> Result<Value> {
             for l in &mut d.layers {
                 map_node_colors(Arc::make_mut(l), &f, true, true);
             }
-            for sw in &mut d.swatches {
+            for sw in d.swatches_iter_mut() {
                 if let vectorcraft_color::Paint::Solid { color, .. } = &mut sw.paint {
                     *color = f(*color);
                 }