refactor(ui): make the status chip the only update entry

Remove the update button from the detail actions; the green chip next
to the extension title opens the update dialog on cards, the desktop
drawer and the mobile details page alike.

ui/flutter/lib/features/extensions/presentation/pages/extension_details_page.dart

@@ -8,6 +8,7 @@ import '../../../../shared/theme/app_palette.dart';
 import '../../../../shared/widgets/detail/app_detail_surface.dart';
 import '../../application/extensions_controller.dart';
 import '../widgets/extension_detail_view.dart';
+import '../widgets/extension_update_dialog.dart';
 import '../widgets/extension_update_status.dart';
 
 class ExtensionDetailsPage extends ConsumerWidget {
@@ -26,7 +27,13 @@ class ExtensionDetailsPage extends ConsumerWidget {
       title: item?.title ?? context.l10n.extensions,
       onBack: () => context.canPop() ? context.pop() : context.go('/extensions'),
       titleTrailing: _canUpdate(stateAsync.value, item)
-          ? ExtensionUpdateStatus(label: context.l10n.extensionCanUpdate)
+          ? ExtensionUpdateStatus(
+              key: const ValueKey('extension-details-update-mobile'),
+              label: context.l10n.extensionCanUpdate,
+              onTap: item?.installed == null
+                  ? null
+                  : () => showExtensionUpdateDialog(context, item!.installed!),
+            )
           : null,
       child: item == null
           ? Center(

ui/flutter/lib/features/extensions/presentation/widgets/extension_detail_view.dart

@@ -35,12 +35,19 @@ class ExtensionDetailDrawer extends ConsumerWidget {
     final installed = item?.installed;
     final canUpdate =
         item != null && installed != null && (state?.updateFlags.containsKey(installed.identity) ?? false);
+    final updateChip = canUpdate
+        ? ExtensionUpdateStatus(
+            key: const ValueKey('extension-details-update'),
+            label: context.l10n.extensionCanUpdate,
+            onTap: () => showExtensionUpdateDialog(context, installed),
+          )
+        : null;
     return AppDetailDrawer(
       open: item != null,
       title: item?.title ?? '',
       onClose: onClose,
       drawerKey: const ValueKey('extension-details-drawer'),
-      titleTrailing: canUpdate ? ExtensionUpdateStatus(label: context.l10n.extensionCanUpdate) : null,
+      titleTrailing: updateChip,
       child: item == null ? const SizedBox.shrink() : ExtensionDetailView(item: item!),
     );
   }
@@ -134,15 +141,6 @@ class ExtensionDetailView extends ConsumerWidget {
                     _runAction(context, () => ref.read(extensionsControllerProvider.notifier).installFromStore(store)),
                 child: Text(context.l10n.extensionInstall),
               ),
-            if (installed != null && canUpdate)
-              AppLoadingButton(
-                key: const ValueKey('extension-details-update'),
-                loading: false,
-                variant: AppLoadingButtonVariant.primary,
-                icon: const Icon(Icons.upgrade, size: 16),
-                onPressed: busy ? null : () => showExtensionUpdateDialog(context, installed),
-                child: Text(context.l10n.extensionUpdateAction),
-              ),
             if (installed != null && !canUpdate)
               AppLoadingButton(
                 key: const ValueKey('extension-details-installed'),