feat(pwa): app icon shortcuts for Quick Dump, new task and shopping list open their input

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/App.tsx

@@ -245,6 +245,34 @@ export const App: React.FC = () => {
   };
 
   const { isMenuOpen, setIsMenuOpen, closeMenu, setGroups, primaryAction, setPrimaryAction } = useMobileActions();
+  const primaryActionRef = useRef(primaryAction);
+  primaryActionRef.current = primaryAction;
+
+  // App icon shortcuts (manifest "shortcuts", long-press on the icon): open the tab and its input right away.
+  // ?shortcut=quickdump|task|list; the old links (?mode=capture, ?tab=triage) still lead to the Quick Dump.
+  const [pendingShortcut, setPendingShortcut] = useState<ActiveTab | null>(() => {
+    const params = new URLSearchParams(window.location.search);
+    const target = params.get('shortcut') || (params.get('mode') === 'capture' || params.get('tab') === 'triage' ? 'quickdump' : '');
+    return ({ quickdump: 'triage', task: 'tasks', list: 'lists' } as Record<string, ActiveTab>)[target] || null;
+  });
+  useEffect(() => {
+    if (!pendingShortcut || !user) return;
+    if (activeTab !== pendingShortcut) {
+      setActiveTab(pendingShortcut);
+      return;
+    }
+    const target = pendingShortcut;
+    setPendingShortcut(null);
+    const url = new URL(window.location.href);
+    ['shortcut', 'mode', 'tab'].forEach((k) => url.searchParams.delete(k));
+    window.history.replaceState({}, '', url.pathname + url.search + url.hash);
+    // The view registers its "+" action once it is mounted, so wait a moment (no cleanup: resetting
+    // pendingShortcut above re-runs this effect and must not cancel the timer)
+    window.setTimeout(() => {
+      if (target === 'triage') handleTriggerAddButton();
+      else if (window.innerWidth < 640 || target === 'lists') primaryActionRef.current?.();
+    }, 400);
+  }, [pendingShortcut, user?.id, activeTab]);
 
   useEffect(() => {
     closeMenu();