fix(web): replace Flutter default placeholders with Recl∆Im branding

The generated web target still carried 'reclaim_app' titles and the
'A new Flutter project.' description. Set the document title,
apple-mobile-web-app-title, PWA manifest name/short_name to the
display mark Recl∆Im and give both the index meta and the manifest
a real product description. The Dart package identifier reclaim_app
stays — only the user-facing strings change.

Signed-off-by: flemming-it <sf@flemming.it>

app/web/manifest.json

@@ -1,11 +1,11 @@
 {
-    "name": "reclaim_app",
-    "short_name": "reclaim_app",
+    "name": "Recl∆Im",
+    "short_name": "Recl∆Im",
     "start_url": ".",
     "display": "standalone",
     "background_color": "#0175C2",
     "theme_color": "#0175C2",
-    "description": "A new Flutter project.",
+    "description": "Recl∆Im — Pflicht-basierte Wirkungsanalyse für Rechtsnormen, auf der Ch∆In-Plattform.",
     "orientation": "portrait-primary",
     "prefer_related_applications": false,
     "icons": [