feat(pwa): add web share target for text and images with offline queue

frontend/src/App.tsx

@@ -67,6 +67,7 @@ import { UserAvatar } from './components/UserAvatar';
 import { CommandPalette } from './components/CommandPalette';
 import { AppFooter } from './components/AppFooter';
 import { AboutModal } from './components/AboutModal';
+import { consumePendingShares, formatSharedThought } from './lib/shareTarget';
 import { APP_VERSION } from './version';
 
 type ActiveTab =
@@ -555,6 +556,46 @@ export const App: React.FC = () => {
     );
   }, [authStatus.demoMode, authStatus.demoResetInSeconds]);
 
+  // Web Share Target: import shared thoughts from external apps
+  useEffect(() => {
+    if (!user) return;
+    const params = new URLSearchParams(window.location.search);
+    const hasPendingShare = params.get('shared') === 'pending';
+
+    const processShares = async () => {
+      try {
+        const shares = await consumePendingShares();
+        if (shares.length === 0) return;
+
+        let importedCount = 0;
+        for (const share of shares) {
+          const content = formatSharedThought(share);
+          if (content) {
+            await api.captureThought(content, 'normal', 'manual', '', { target: 'inbox' });
+            importedCount++;
+          }
+        }
+
+        if (importedCount > 0) {
+          triggerHaptic(15);
+          setDemoNotice('Erfolgreich im Quick Dump abgelegt');
+          setTimeout(() => setDemoNotice(null), 4000);
+          refreshAll();
+        }
+      } catch (err) {
+        console.error('Fehler beim Import geteilter Daten:', err);
+      } finally {
+        if (hasPendingShare) {
+          const url = new URL(window.location.href);
+          url.searchParams.delete('shared');
+          window.history.replaceState({}, '', url.pathname + (url.search ? url.search : '') + url.hash);
+        }
+      }
+    };
+
+    processShares();
+  }, [user, refreshAll]);
+
   // The demo database was reset: drop cached answers of the old data, remount the views (they load
   // fresh data), refresh counters and the countdown. Sessions stay valid (fixed demo account IDs).
   const handleDemoReset = useCallback(() => {