v0.12.31 multiple UI changes

frontend/src/pages/Chat.jsx

@@ -447,27 +447,50 @@ export default function Chat() {
     setActiveGroupId(id);
     if (isMobile) {
       setShowSidebar(false);
-      // Push a history entry so swipe-back returns to sidebar instead of exiting the app
-      window.history.pushState({ rosterchirpChatOpen: true }, '');
+      // The mount sentinel covers the first back gesture — no extra push needed here
     }
     // Clear notifications and unread count for this group
     setNotifications(prev => prev.filter(n => n.groupId !== id));
     setUnreadGroups(prev => { const next = new Map(prev); next.delete(id); return next; });
   };
 
-  // Handle browser back gesture on mobile — return to sidebar instead of exiting
+  // Establish one history sentinel on mount (mobile only) so back gestures are
+  // always interceptable without accumulating extra entries.
   useEffect(() => {
-    const handlePopState = (e) => {
-      if (isMobile && activeGroupId) {
+    if (window.innerWidth < 768) {
+      window.history.replaceState({ rc: 'chat' }, '');
+    }
+  }, []);
+
+  // Handle browser back gesture on mobile — step through the navigation hierarchy:
+  //   chat open  →  list view for the current page  →  Messages  →  exit app
+  useEffect(() => {
+    const handlePopState = () => {
+      if (!isMobile) return;
+
+      if (activeGroupId) {
+        // Close the open chat, stay on the current page's list (chat or groupmessages)
         setShowSidebar(true);
         setActiveGroupId(null);
-        // Push another entry so subsequent back gestures are also intercepted
-        window.history.pushState({ rosterchirpChatOpen: true }, '');
+        setChatHasText(false);
+        window.history.pushState({ rc: 'chat' }, '');
+        return;
       }
+
+      if (page !== 'chat') {
+        // On a secondary page (groupmessages / users / groups / schedule / hostpanel)
+        // — return to the default Messages page
+        setPage('chat');
+        window.history.pushState({ rc: 'chat' }, '');
+        return;
+      }
+
+      // Already at root (Messages list, no chat open) — let the browser handle
+      // it so the next gesture actually exits the PWA. Don't re-push.
     };
     window.addEventListener('popstate', handlePopState);
     return () => window.removeEventListener('popstate', handlePopState);
-  }, [isMobile, activeGroupId]);
+  }, [isMobile, activeGroupId, page]);
 
   // Update page title AND PWA app badge with total unread count
   useEffect(() => {