Artboards: Duplicate Artboards, Copy and Cut take every selected artboard

With several artboards selected, the Artboards panel menu's Duplicate
Artboards copied only the active one, and Copy and Cut with the
Artboard tool took only the tool's active artboard.

artboard.duplicate, artboard.copy and artboard.cut now take `indices`,
and without `index` or `indices` they act on the artboards the
Artboard tool has selected. Duplicate Artboards passes the selected
artboards and selects the copies. Duplicate and Cut are one undo step
each, and Paste adds every copied artboard back, with its art, in one
undo step. The copies keep their places relative to each other,
together right of the last artboard. A cut fails when it names every
artboard.

Docs: docs/mcp.md, docs/target-app-parity.md.

crates/engine/src/cmd/edit.rs

@@ -83,7 +83,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Paste",
             ["Edit"],
             Some("Cmd+V"),
-            "{center?: [x, y], dx?, dy?, swatchConflict?} paste centred on `center` (the app passes the view centre), else offset by dx/dy (default: the Paste Offset preference). Pasting brings the image blobs, symbols, patterns, global and spot swatches (with the tint swatches of the tints used), gradient swatches, graphic styles, character and paragraph styles and brushes the objects use; one of the same name that differs comes in renamed. swatchConflict, for a swatch whose name the document gives another colour (clipboard.conflicts): \"merge\" (default: the objects take the document's swatch) | \"add\" (the pasted swatch comes in renamed) | {name: \"merge\"|\"add\"}. With Paste Remembers Layers on (layer.pasteRemembersLayers), objects go back into the layers they came from (by name; made when missing). An artboard copied with artboard.copy comes with its art, right of the last artboard (the other paste commands but Paste on All Artboards: where it was), its art back in the layers it came from → {ids, artboard: the new artboard's index or null, added: resources added, merged: conflicts merged, renamed: [{kind, from, to}]}",
+            "{center?: [x, y], dx?, dy?, swatchConflict?} paste centred on `center` (the app passes the view centre), else offset by dx/dy (default: the Paste Offset preference). Pasting brings the image blobs, symbols, patterns, global and spot swatches (with the tint swatches of the tints used), gradient swatches, graphic styles, character and paragraph styles and brushes the objects use; one of the same name that differs comes in renamed. swatchConflict, for a swatch whose name the document gives another colour (clipboard.conflicts): \"merge\" (default: the objects take the document's swatch) | \"add\" (the pasted swatch comes in renamed) | {name: \"merge\"|\"add\"}. With Paste Remembers Layers on (layer.pasteRemembersLayers), objects go back into the layers they came from (by name; made when missing). Artboards copied with artboard.copy come with their art, together right of the last artboard as they lay (the other paste commands but Paste on All Artboards: where they were), their art back in the layers it came from, and the Artboard tool, when chosen, selects them → {ids, artboard: the first new artboard's index or null, artboards: the new artboards' indices, added: resources added, merged: conflicts merged, renamed: [{kind, from, to}]}",
             has_clipboard,
             |s, p| paste(s, p, PasteMode::Offset)
         ),
@@ -515,16 +515,19 @@ fn paste_clip(s: &mut Session, p: &Value, mode: PasteMode, clip: &Clipboard, cho
     let st = s.doc()?;
     let same_doc = clip.source_doc == Some(st.uid);
     let parent = st.target_parent()?;
-    // A copied artboard comes back with its art: right of the last artboard, or where it was
-    // (Paste in Place, in Front, in Back). Paste on All Artboards pastes only the art.
-    let board = clip
-        .artboard
-        .as_ref()
+    // Copied artboards come back with their art: together right of the last artboard, as they lay,
+    // or where they were (Paste in Place, in Front, in Back). Paste on All Artboards pastes only the
+    // art.
+    let boards = clip
+        .artboards
+        .iter()
+        .map(|a| a.rect)
+        .reduce(|a, b| a.union(b))
         .filter(|_| mode != PasteMode::AllArtboards)
-        .map(|a| (a, if mode == PasteMode::Offset { super::panelcmds::beside_artboards(&st.doc, a.rect) } else { Vec2::ZERO }));
+        .map(|all| (&clip.artboards, if mode == PasteMode::Offset { super::panelcmds::beside_artboards(&st.doc, all) } else { Vec2::ZERO }));
     // Paste Remembers Layers (not while isolating a group: pastes stay in it); an artboard's art
     // always goes back into its layers.
-    let remember = (st.doc.paste_remembers_layers || board.is_some()) && parent.is_some_and(|p| st.doc.node(p).is_some_and(Node::is_layer));
+    let remember = (st.doc.paste_remembers_layers || boards.is_some()) && parent.is_some_and(|p| st.doc.node(p).is_some_and(Node::is_layer));
     // Front/back: relative to the selection (top-most / bottom-most selected object); with
     // nothing selected, the top / bottom of the current layer.
     let anchor = match mode {
@@ -535,7 +538,7 @@ fn paste_clip(s: &mut Session, p: &Value, mode: PasteMode, clip: &Clipboard, cho
         }
         _ => None,
     };
-    let placements: Vec<Affine> = match (mode, board) {
+    let placements: Vec<Affine> = match (mode, boards) {
         (_, Some((_, dv))) => vec![Affine::translate(dv)],
         (PasteMode::Offset | PasteMode::Library, None) => vec![match point_param(p, "center") {
             Some(c) => clip.bounds().map_or(Affine::IDENTITY, |b| Affine::translate(c - b.center())),
@@ -548,9 +551,13 @@ fn paste_clip(s: &mut Session, p: &Value, mode: PasteMode, clip: &Clipboard, cho
         // In place, in front, in back: onto the active artboard when the UI names it.
         _ => vec![onto_artboard(&st.doc, p, clip)],
     };
-    let (ids, imported, artboard) = s.edit(mode.label(), |d, sel| {
+    let (ids, imported, artboards) = s.edit(mode.label(), |d, sel| {
         let imported = clip.import_into(d, choices, same_doc);
-        let artboard = board.map(|(a, dv)| super::panelcmds::push_artboard_copy(d, a, a.rect + dv));
+        let artboards: Vec<usize> = boards
+            .into_iter()
+            .flat_map(|(all, dv)| all.iter().map(move |a| (a, dv)))
+            .map(|(a, dv)| super::panelcmds::push_artboard_copy(d, a, a.rect + dv))
+            .collect();
         let mut layers: BTreeMap<&str, NodeId> = BTreeMap::new();
         // Objects pasted into each parent so far (keeps their order in front and back pastes).
         let mut placed: BTreeMap<Option<NodeId>, usize> = BTreeMap::new();
@@ -585,15 +592,16 @@ fn paste_clip(s: &mut Session, p: &Value, mode: PasteMode, clip: &Clipboard, cho
         // Pasted type arrives without the layout bounds cache: fill it so boxes and alignment are
         // right away (opening the file later would, but paste must not depend on a reopen).
         super::typecmd::refresh_bounds_of(d, &new_ids);
-        Ok((new_ids, imported, artboard))
+        Ok((new_ids, imported, artboards))
     })?;
-    // The Artboard tool takes the pasted artboard.
-    if let Some(i) = artboard.filter(|_| s.tool_id() == "artboard") {
-        s.set_tool_option("active", &json!(i));
+    // The Artboard tool selects the pasted artboards, the first one active.
+    if !artboards.is_empty() && s.tool_id() == "artboard" {
+        s.set_tool_option("selected", &json!(artboards));
     }
     Ok(json!({
         "ids": ids.iter().map(|i| i.0).collect::<Vec<_>>(),
-        "artboard": artboard,
+        "artboard": artboards.first(),
+        "artboards": artboards,
         "added": imported.added,
         "merged": imported.merged,
         "renamed": imported.renamed,