feat(aigc): add image preview and improve detail layout

- restructure aigc detail page flex layout to separate preview and control sections
- update ResultPreview styles to fill full width and height
- add click-to-preview functionality for result images
- add auto-hide delay and fix state management for GiftPointsToast component
- adjust video component handling for fullscreen display mode

src/pages-aigc/detail/detail.vue

@@ -4,15 +4,17 @@
 
     <view class="aigc-detail-content">
       <template v-if="taskDetail">
-        <ResultPreview v-if="result.cover" :result="result" />
-        <ResultMeta :items="metaItems" />
-        <ResultActions :saving="isSaving" :media-type="result.mediaType" :share-ready="Boolean(shareKey)"
-          :share-preparing="isPreparingShare" @save="handleSave" @prepare-share="handlePrepareShare" />
+        <ResultPreview v-if="result.cover" class="aigc-detail-preview" :result="result" />
+        <view class="aigc-detail-controls">
+          <ResultMeta :items="metaItems" />
+          <ResultActions :saving="isSaving" :media-type="result.mediaType" :share-ready="Boolean(shareKey)"
+            :share-preparing="isPreparingShare" @save="handleSave" @prepare-share="handlePrepareShare" />
 
-        <view class="aigc-detail-text-actions">
-          <view class="aigc-detail-text-action" @tap="handleRegenerate">再生成一版</view>
-          <view class="aigc-detail-text-action" @tap="handleChangeTemplate">换个模板</view>
-          <view class="aigc-detail-text-action" @tap="handleOpenRecords">历史记录</view>
+          <view class="aigc-detail-text-actions">
+            <view class="aigc-detail-text-action" @tap="handleRegenerate">再生成一版</view>
+            <view class="aigc-detail-text-action" @tap="handleChangeTemplate">换个模板</view>
+            <view class="aigc-detail-text-action" @tap="handleOpenRecords">历史记录</view>
+          </view>
         </view>
       </template>
     </view>