feat(statusbar): selection cycling for overlapping objects (SC pill)

Add a click_hits_all hit-test and an SC pill that, when on, makes
repeated clicks at the same spot step through the overlapping objects
there (nearest first) instead of accumulating the selection. The whole
cycling path is gated behind the toggle, so default picking is unchanged
when it is off.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ui/statusbar.rs

@@ -67,6 +67,8 @@ impl StatusBar {
         quick_properties: bool,
         // True when the selection filter is excluding at least one type.
         selection_filter_active: bool,
+        // Whether selection cycling is enabled.
+        selection_cycling: bool,
         // Which pills the user has chosen to show on the bar.
         config: &'a StatusBarConfig,
     ) -> Element<'a, Message> {
@@ -213,6 +215,12 @@ impl StatusBar {
                 "Selection Filtering\nLimit which object types can be picked",
             ));
         }
+        if vis(StatusPill::SelCycle) {
+            right_status = right_status.push(tip(
+                toggle_pill("SC", selection_cycling, Message::ToggleSelectionCycling),
+                "Selection Cycling\nRepeat-click to step through overlapping objects",
+            ));
+        }
         if vis(StatusPill::Vp) && !vp_label.is_empty() {
             right_status = right_status.push(tip(
                 status_pill(vp_label).into(),

src/ui/statusbar_config.rs

@@ -27,6 +27,7 @@ pub enum StatusPill {
     Isolate,
     QuickProps,
     SelFilter,
+    SelCycle,
     Vp,
     CleanScreen,
 }
@@ -51,6 +52,7 @@ impl StatusPill {
         StatusPill::Isolate,
         StatusPill::QuickProps,
         StatusPill::SelFilter,
+        StatusPill::SelCycle,
         StatusPill::Vp,
         StatusPill::CleanScreen,
     ];
@@ -74,6 +76,7 @@ impl StatusPill {
             StatusPill::Isolate => "isolate",
             StatusPill::QuickProps => "quickprops",
             StatusPill::SelFilter => "selfilter",
+            StatusPill::SelCycle => "selcycle",
             StatusPill::Vp => "vp",
             StatusPill::CleanScreen => "cleanscreen",
         }
@@ -98,6 +101,7 @@ impl StatusPill {
             StatusPill::Isolate => "Isolate Objects",
             StatusPill::QuickProps => "Quick Properties",
             StatusPill::SelFilter => "Selection Filtering",
+            StatusPill::SelCycle => "Selection Cycling",
             StatusPill::Vp => "Viewport Count",
             StatusPill::CleanScreen => "Clean Screen",
         }