ui: the viewport draws the analysis setup's symbols, with toggles

The setup's symbols (fieldcraft_render::glyphs) are built with the display
data and drawn over the model in every style, at the drawn nodes (a results
plot's deformed shape), muted over results; the clipping radius holds them.
Theme tokens give their colours in light and dark. The browser's Loads & BCs
and Interactions rows get eye toggles (ui.set show_loads, show_interactions),
also in the view menu. The GPU viewport draws reference point names with the
interface's font; the bottom left says which definitions are sampled.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

crates/ui-egui/src/results.rs

@@ -86,7 +86,7 @@ impl Plot {
 
     /// The node's position in the plot, if it is drawn.
     pub fn node_position(&self, label: u32) -> Option<Vec3> {
-        self.display.nodes.binary_search_by_key(&label, |n| n.label).ok().and_then(|i| self.display.nodes.get(i)).map(|n| n.p)
+        self.display.node_position(label)
     }
 }