refactor(dialogs): unify button styles and layout in dialog components

- Updated VCardActions in multiple dialog components to use a consistent class `app-dialog-actions` for styling.
- Changed button variants to `flat` for primary actions and `tonal` for secondary actions across various dialogs.
- Adjusted padding and spacing for buttons to improve layout consistency.
- Enhanced responsiveness for dialog actions in mobile views.

src/components/dialog/StorageCustomConfigDialog.vue

@@ -89,8 +89,9 @@ function handleDone() {
           </VCol>
         </VRow>
       </VCardText>
-      <VCardActions class="pt-3">
-        <VBtn @click="handleDone" prepend-icon="mdi-content-save" class="px-5">
+      <VCardActions class="app-dialog-actions">
+        <VSpacer />
+        <VBtn color="primary" variant="flat" @click="handleDone" prepend-icon="mdi-content-save" class="px-5">
           {{ t('common.save') }}
         </VBtn>
       </VCardActions>