Live Paint: Make and Merge refuse type, images and other objects that aren't paths

Live Paint builds its faces and edges from path outlines alone. Make,
Merge and the Live Paint Bucket put every selected object among the
group's hidden sources, so type, an image, a symbol, a blend or a group
holding one of them vanished from the canvas. They now refuse such a
selection before changing anything ("Live Paint takes paths and compound
paths: convert type, images and other objects to paths first"), as type
and raster images can't go into a Live Paint group directly
(https://helpx.adobe.com/illustrator/desktop/paint-and-fill/learn-painting-basics/create-live-paint-groups.html).
One predicate, vectorcraft_tools::builder::live_paint_takes (Live Paint
groups, paths, compound paths and groups of them), decides it for Make,
Merge and the Properties panel's Merge Live Paint, which no longer shows
for a selection Merge refuses. The message has an @msg row in every
catalog.

Tests: tests_build::live_paint_refuses_type_and_images_and_changes_nothing
(Merge, Make and the Bucket with type, an image or a group holding type:
refused, document, selection and undo history unchanged; a group of
paths and a path still merge) and
panels::properties::tests::merge_live_paint_is_a_quick_action_for_a_live_paint_group_and_more
(hidden with type selected). Both fail without the change.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/engine/src/cmd/buildcmds.rs

@@ -58,7 +58,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Make",
             ["Object", "Live Paint"],
             Some("Cmd+Alt+X"),
-            "{ids?|id?} build a Live Paint group from the selected paths; with a Live Paint group among them, add the others to it as livePaint.merge does → {id, faces, edges}",
+            "{ids?|id?} build a Live Paint group from the selected paths (paths, compound paths and groups of them; type, images and other objects are refused, nothing changes); with a Live Paint group among them, add the others to it as livePaint.merge does → {id, faces, edges}",
             has_selection_or_ids,
             lp_make
         ),
@@ -67,7 +67,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Merge",
             ["Object", "Live Paint"],
             None,
-            "{ids?|id?} add the other selected paths (and Live Paint groups) to the bottom-most Live Paint group, keeping its id, its paint and its own properties (name, lock, visibility, transparency, appearance, opacity mask, graphic style link) → {id, faces, edges}",
+            "{ids?|id?} add the other selected paths (compound paths, groups of paths and Live Paint groups too; type, images and other objects are refused, nothing changes) to the bottom-most Live Paint group, keeping its id, its paint and its own properties (name, lock, visibility, transparency, appearance, opacity mask, graphic style link) → {id, faces, edges}",
             has_multi_or_ids,
             lp_merge
         ),
@@ -609,9 +609,24 @@ fn merged_gap_options(groups: &[GapOptions]) -> GapOptions {
     if !bottom.detect && groups.iter().any(|g| g.detect) { GapOptions { detect: true, size: GapSize::Small, ..bottom } } else { bottom }
 }
 
+/// Refuse `roots` when one of them is something Live Paint can't take ([`b::live_paint_takes`]):
+/// its faces and edges come from path outlines alone, so type or an image would vanish among the
+/// group's hidden sources. Checked before anything changes.
+fn check_live_paint_takes(d: &Document, roots: &[NodeId]) -> Result<()> {
+    for r in roots {
+        if !b::live_paint_takes(d.node(*r).ok_or(EngineError::NoNode(*r))?) {
+            return Err(EngineError::Other(
+                "Live Paint takes paths and compound paths: convert type, images and other objects to paths first".into(),
+            ));
+        }
+    }
+    Ok(())
+}
+
 /// Make a Live Paint group from `roots`, or add them to the first Live Paint group among them
 /// as Merge does; returns (group, faces, edges).
 fn make_live(d: &mut Document, sel: &mut Selection, roots: &[NodeId]) -> Result<(NodeId, usize, usize)> {
+    check_live_paint_takes(d, roots)?;
     if roots.iter().any(|r| d.node(*r).is_some_and(is_live_paint)) {
         return merge_live(d, sel, roots);
     }
@@ -644,6 +659,7 @@ fn merge_live(d: &mut Document, sel: &mut Selection, roots: &[NodeId]) -> Result
         .copied()
         .find(|r| d.node(*r).is_some_and(is_live_paint))
         .ok_or_else(|| EngineError::Other("Live Paint Merge: select a Live Paint group and the paths to add".into()))?;
+    check_live_paint_takes(d, roots)?;
     let old = d.node(target).cloned().ok_or(EngineError::NoNode(target))?;
     // Paint to carry over: (point inside face, fill) and (point on edge, stroke).
     let keep_faces: Vec<(Point, Paint)> = b::faces(&old)