Hide and show joints in the browser, like other items (#1168)

Fixes #1160.

crates/ui-egui/src/control.rs

@@ -264,11 +264,12 @@ fn dispatch(app: &mut SolveApp, ctx: &egui::Context, method: &str, p: &Value) ->
         }
         "ui.set" => {
             // What is hidden lives in the session (`browser.visibility`); `ui.set` still sets it.
-            const VIS: [(&str, &str); 4] = [
+            const VIS: [(&str, &str); 5] = [
                 ("hiddenBodies", "hidden_bodies"),
                 ("hiddenOrigin", "hidden_origin"),
                 ("hiddenSketches", "hidden_sketches"),
                 ("shownSketches", "shown_sketches"),
+                ("hiddenJoints", "hidden_joints"),
             ];
             let mut cur = serde_json::to_value(&app.ui).unwrap_or(json!({}));
             let mut vis = serde_json::to_value(&app.session.visibility).unwrap_or(json!({}));