fix(catalog): prevent grid card overflow on mobile

lib/main.dart

@@ -1016,7 +1016,8 @@ class _MosaicHomePageState extends State<MosaicHomePage>
       itemCount: _catalog.length,
       gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
         crossAxisCount: 2,
-        childAspectRatio: 1.2,
+        // Mehr vertikaler Platz pro Card, damit Name/Hex/Delete nicht überlaufen.
+        childAspectRatio: 0.92,
         mainAxisSpacing: 8,
         crossAxisSpacing: 8,
       ),
@@ -1051,10 +1052,13 @@ class _MosaicHomePageState extends State<MosaicHomePage>
                       const Spacer(),
                       IconButton(
                         visualDensity: VisualDensity.compact,
+                        padding: EdgeInsets.zero,
+                        constraints:
+                            const BoxConstraints.tightFor(width: 30, height: 30),
                         onPressed: _catalog.length <= 1
                             ? null
                             : () => _deleteEntry(entry),
-                        icon: const Icon(Icons.delete_outline),
+                        icon: const Icon(Icons.delete_outline, size: 20),
                       ),
                     ],
                   ),