feat(super-editor): invalidate viewport geometry on sidebar-toggle (SD-3326)

ui.viewport.observe now fires when the comments rail opens or closes.
The rail toggle shifts document geometry without a guaranteed layout
repaint, so overlay consumers' cached rects would silently go stale.
Bridges the existing sidebar-toggle signal into a geometry invalidation,
reusing the 'layout' reason (consumers only re-query, so no new public
reason is added).

Author: caio-pizzol

packages/super-editor/src/ui/create-super-doc-ui.ts

@@ -1013,6 +1013,12 @@ export function createSuperDocUI(options: SuperDocUIOptions): SuperDocUI {
   };
   const onWindowScrollGeometry = () => scheduleGeometry('scroll');
   const onWindowResizeGeometry = () => scheduleGeometry('resize');
+  // The comments rail toggling shifts/reflows document geometry but does
+  // not reliably emit a layout repaint on its own, so cached rects would
+  // silently go stale. Bridge the explicit sidebar-toggle signal into a
+  // geometry invalidation. Reuses the 'layout' reason — consumers only
+  // re-query on it, so no new public reason is warranted.
+  const onGeometrySidebar = () => scheduleGeometry('layout');
   let domGeometryAttached = false;
   const attachDomGeometryListeners = () => {
     if (domGeometryAttached || typeof window === 'undefined') return;
@@ -1046,9 +1052,11 @@ export function createSuperDocUI(options: SuperDocUIOptions): SuperDocUI {
     // zoom drives geometry (post-paint, tagged via onGeometryLayout) — separate
     // from the slice recompute that SUPERDOC_EVENTS triggers.
     superdoc.on?.('zoomChange', onGeometryZoom);
+    superdoc.on?.('sidebar-toggle', onGeometrySidebar);
     teardown.push(() => {
       SUPERDOC_EVENTS.forEach((name) => superdoc.off?.(name, scheduleNotify));
       superdoc.off?.('zoomChange', onGeometryZoom);
+      superdoc.off?.('sidebar-toggle', onGeometrySidebar);
     });
   }
 

packages/super-editor/src/ui/viewport.test.ts

@@ -734,4 +734,19 @@ describe('ui.viewport.observe — repaint reason (SD-3311 regression)', () => {
     expect(events).toEqual([{ reason: 'layout' }]);
     ui.destroy();
   });
+
+  it('fires a geometry invalidation on sidebar-toggle (reason "layout")', async () => {
+    // The comments rail toggling shifts geometry without a guaranteed
+    // layout repaint; observe must still notify so cached rects re-query.
+    const { superdoc, emitSuperdoc } = makeGeometryStub();
+    const ui = createSuperDocUI({ superdoc });
+    const events: Array<{ reason: string }> = [];
+    ui.viewport.observe((e) => events.push(e));
+
+    emitSuperdoc('sidebar-toggle', true);
+    await nextFrame();
+
+    expect(events).toEqual([{ reason: 'layout' }]);
+    ui.destroy();
+  });
 });