feat(properties): refine quick properties

- Keep the floating panel near the selection and inside the viewport
- Persist the toggle and hide the panel without a selection
- Show only Material in 3D Visualization

src/app/update/file.rs

@@ -287,6 +287,7 @@ impl OpenCADStudio {
             default_save_format: self.default_save_format.clone(),
             pick_add: self.pick_add,
             pick_drag_rect: self.pick_drag_rect,
+            quick_properties: self.quick_properties,
             bg_color: self.default_bg_color.map(f4_to_u3),
             paper_bg_color: self.default_paper_bg_color.map(f4_to_u3),
             language: self.language,
@@ -325,6 +326,7 @@ impl OpenCADStudio {
             crate::io::canonical_save_format(&s.default_save_format).to_string();
         self.pick_add = s.pick_add;
         self.pick_drag_rect = s.pick_drag_rect;
+        self.quick_properties = s.quick_properties;
         self.default_bg_color = s.bg_color.map(u3_to_f4);
         self.default_paper_bg_color = s.paper_bg_color.map(u3_to_f4);
         if crate::i18n::set_language(s.language).is_ok() {

src/app/update/mod.rs

@@ -3216,6 +3216,11 @@ impl OpenCADStudio {
             }
             Message::ToggleQuickProperties => {
                 self.quick_properties ^= true;
+                if self.quick_properties {
+                    self.quick_properties_anchor =
+                        self.tabs[self.active_tab].last_cursor_screen;
+                }
+                self.save_config();
                 Task::none()
             }
             Message::ToggleSelectionCycling => {
@@ -3226,12 +3231,19 @@ impl OpenCADStudio {
             }
             Message::CycleSelect(handle) => {
                 // Add the picked object to the current selection (accumulate).
+                let quick_properties_anchor = self
+                    .cycle_candidates
+                    .as_ref()
+                    .map(|(point, _)| *point);
                 self.cycle_candidates = None;
                 let i = self.active_tab;
                 self.tabs[i].scene.set_hover_highlight(None);
                 self.tabs[i].scene.select_entity(handle, false);
                 self.tabs[i].scene.expand_selection_for_groups(&[handle]);
                 self.refresh_properties();
+                if let Some(point) = quick_properties_anchor {
+                    self.quick_properties_anchor = point;
+                }
                 Task::none()
             }
             Message::CycleHover(handle) => {

src/app/update/viewport.rs

@@ -3530,6 +3530,10 @@ impl OpenCADStudio {
             sel.left_dragging = false;
         }
 
+        if selection_just_completed {
+            self.quick_properties_anchor = p_full;
+        }
+
         if is_gathering && selection_just_completed {
             let handles: Vec<Handle> = self.tabs[i]
                 .scene