fix(store): wrap docs-panel hint in Expanded to prevent overflow

The 'Documentation' row in the module-detail sheet showed
a RenderFlex horizontal overflow when the sheet is narrow
(~340dp on mobile/portrait). The Row had:
  [Button] [Spacer] [Text(hint)]
without any Expanded/Flexible wrapper, so the hint text could
not break and pushed past the right edge.

Fix: wrap the hint Text in Expanded. Text now wraps to a
second line at narrow widths instead of overflowing. Also
explicitly set crossAxisAlignment.center so the wrapped text
visually aligns with the button on a single baseline.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/pages/store.dart

@@ -2465,7 +2465,12 @@ class _DocsPanel extends StatelessWidget {
     final theme = Theme.of(context);
     final l = AppLocalizations.of(context)!;
     if (future == null) {
+      // Row im Modul-Detail-Sheet kann eng werden (~340 dp).
+      // Hint-Text wird in Expanded gewrappt damit er bricht
+      // statt zu overflowen (CrossAxisAlignment.center hält die
+      // Optik mit dem Button auf einer Höhe).
       return Row(
+        crossAxisAlignment: CrossAxisAlignment.center,
         children: [
           OutlinedButton.icon(
             onPressed: onLoad,
@@ -2473,12 +2478,14 @@ class _DocsPanel extends StatelessWidget {
             label: Text(l.storeLoadDocs),
           ),
           const SizedBox(width: FaiSpace.sm),
-          Text(
+          Expanded(
+            child: Text(
               l.storeDocsHint,
               style: theme.textTheme.bodySmall?.copyWith(
                 color: theme.colorScheme.onSurfaceVariant,
               ),
             ),
+          ),
         ],
       );
     }