M3: component properties keep their order on rename; Make slot asks for the name (#1536, #1537) (#1565)

Properties were listed by name, so a rename moved one. Components now keep prop_order (the names as they were made; a rename keeps the place) and every listing follows it. Make slot opens a name field under the frame's Slot row; Enter makes the slot, Escape cancels, a taken name keeps the field open.

crates/engine/src/cmd/component/instance.rs

@@ -331,7 +331,7 @@ pub(super) fn restore_main(s: &mut Session, p: &Value) -> Result<Value> {
         let Some(mut n) = doc.node(*d).cloned() else { continue };
         if *d == i {
             let defs = restore_prop_defs(doc, &props);
-            n.kind = NodeKind::Component { description: String::new(), props: defs };
+            n.kind = NodeKind::Component { description: String::new(), props: defs, prop_order: Vec::new() };
             n.source = None;
             n.overrides.clear();
             n.prop_refs.clear();