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/content/synthetic.rs

@@ -82,8 +82,15 @@ pub fn large_document(layers: usize) -> DocResult<(Document, NodeId)> {
     let page = doc.first_page().ok_or(figcraft_doc::DocError::Invalid("new document has no page".into()))?;
     let layers = layers.clamp(10, 2_000_000);
     // The shared button component (3 layers), above the screens.
-    let button =
-        doc.create(page, NodeKind::Component { description: String::new(), props: Default::default() }, "Button", 0.0, -120.0, 96.0, 32.0)?;
+    let button = doc.create(
+        page,
+        NodeKind::Component { description: String::new(), props: Default::default(), prop_order: Vec::new() },
+        "Button",
+        0.0,
+        -120.0,
+        96.0,
+        32.0,
+    )?;
     let bg = doc.create(button, NodeKind::Rectangle, "Background", 0.0, 0.0, 96.0, 32.0)?;
     fill(&mut doc, bg, Color::from_rgb8_const(0x0D, 0x99, 0xFF));
     if let Some(n) = doc.node_mut(bg) {

crates/engine/src/content/synthetic_ds.rs

@@ -118,7 +118,7 @@ fn var_id(name: &str) -> String {
 }
 
 fn component() -> NodeKind {
-    NodeKind::Component { description: String::new(), props: BTreeMap::new() }
+    NodeKind::Component { description: String::new(), props: BTreeMap::new(), prop_order: Vec::new() }
 }
 
 fn text(chars: &str) -> NodeKind {