refactor: adapt page header styles for responsive design (#7544)

#### What type of PR is this?

/area ui
/kind improvement
/milestone 2.21.x

#### What this PR does / why we need it:

Adapt page header styles for responsive design

before:

<img width="415" alt="image" src="https://github.com/user-attachments/assets/feee6f09-9a77-4bbf-94c2-77725c9ce76b" />

after:

<img width="416" alt="image" src="https://github.com/user-attachments/assets/60bb07a3-5d34-4cf6-b103-5d1f2206d62d" />

#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/6425

#### Special notes for your reviewer:

#### Does this PR introduce a user-facing change?

```release-note
优化移动端下文章编辑页面的样式
```

ui/console-src/modules/system/plugins/PluginList.vue

@@ -159,33 +159,31 @@ onMounted(() => {
 
   <VPageHeader :title="$t('core.plugin.title')">
     <template #icon>
-      <IconPlug class="mr-2 self-center" />
+      <IconPlug />
     </template>
     <template #actions>
-      <VSpace>
-        <HasPermission :permissions="['*']">
-          <VButton
-            size="sm"
-            @click="$router.push({ name: 'PluginExtensionPointSettings' })"
-          >
-            <template #icon>
-              <IconSettings />
-            </template>
-            {{ $t("core.plugin.actions.extension-point-settings") }}
-          </VButton>
-        </HasPermission>
-
+      <HasPermission :permissions="['*']">
         <VButton
-          v-permission="['system:plugins:manage']"
-          type="secondary"
-          @click="pluginInstallationModalVisible = true"
+          size="sm"
+          @click="$router.push({ name: 'PluginExtensionPointSettings' })"
         >
           <template #icon>
-            <IconAddCircle />
+            <IconSettings />
           </template>
-          {{ $t("core.common.buttons.install") }}
+          {{ $t("core.plugin.actions.extension-point-settings") }}
         </VButton>
-      </VSpace>
+      </HasPermission>
+
+      <VButton
+        v-permission="['system:plugins:manage']"
+        type="secondary"
+        @click="pluginInstallationModalVisible = true"
+      >
+        <template #icon>
+          <IconAddCircle />
+        </template>
+        {{ $t("core.common.buttons.install") }}
+      </VButton>
     </template>
   </VPageHeader>