mobile: preserve dashboard scroll on back; allow iOS edge-swipe

src/components/Dashboard/index.jsx

@@ -1,4 +1,4 @@
-import React, { lazy, Suspense } from 'react';
+import React, { lazy, Suspense, useEffect } from 'react';
 import { connect } from 'react-redux';
 import Obstruction from 'obstruction';
 
@@ -18,7 +18,29 @@ const DashboardLoading = () => (
   </Grid>
 );
 
+// Persist the dashboard's scroll position across navigation so closing a route
+// returns the user to where they were. Stored in sessionStorage keyed by
+// dongleId so different devices don't stomp each other.
+const useDashboardScrollRestore = (dongleId) => {
+  useEffect(() => {
+    if (!dongleId) return undefined;
+    const key = `dashboard-scroll-${dongleId}`;
+
+    const saved = sessionStorage.getItem(key);
+    if (saved !== null) {
+      // Defer to next frame so children have a chance to lay out before we scroll.
+      requestAnimationFrame(() => window.scrollTo(0, parseInt(saved, 10)));
+    }
+
+    const onScroll = () => sessionStorage.setItem(key, String(window.scrollY));
+    window.addEventListener('scroll', onScroll, { passive: true });
+    return () => window.removeEventListener('scroll', onScroll);
+  }, [dongleId]);
+};
+
 const Dashboard = ({ primeNav, device, dongleId }) => {
+  useDashboardScrollRestore(primeNav ? null : dongleId);
+
   if (!device || !dongleId) {
     return <DashboardLoading />;
   }

src/components/utils/PullDownReload.jsx

@@ -60,6 +60,14 @@ class PullDownReload extends Component {
       return;
     }
 
+    // Don't capture touches that start near the screen edges — those are
+    // iOS' system back-swipe gestures and we shouldn't preventDefault on them.
+    const x = ev.touches[0].pageX;
+    const edgeWidth = 30;
+    if (x < edgeWidth || x > window.innerWidth - edgeWidth) {
+      return;
+    }
+
     this.setState({ startY: ev.touches[0].pageY });
   }