fix(viral-video): 时长选择恢复为原生 Select，仅改选项为15-30秒每秒一档

- 移除自定义 DurationWheelPicker 组件引用，恢复原来的 Ant Design Select
- 选项从 [15,20,30,45,60] 改为 15-30 秒每秒一档（共16项）
- 默认值保持20秒（上轮已改）
- 样式、交互、弹层方式与其他字段完全一致，无任何 UI 改动

apps/web/src/pages/viral-video/ViralVideoPage.tsx

@@ -30,7 +30,6 @@ import { uploadAssetDirect, getAssetLibraries, getAssetsByKind, type AssetItem }
 import { fetchPresetVoices } from "@/api/voices"
 import { getVoiceClones, getVoiceClonePreview } from "@/api/voice-clone"
 import type { VoiceClone } from "@/api/voice-clone"
-import DurationWheelPicker from "@/components/common/DurationWheelPicker"
 import {
   FUSION_LEVELS,
   STYLE_STRENGTHS,
@@ -224,6 +223,7 @@ const RATIOS = [
   { v: "16:9", label: "16:9 横屏（B站/YouTube）" },
   { v: "1:1", label: "1:1 方形（小红书）" },
 ]
+const DURATIONS = Array.from({ length: 16 }, (_, i) => 15 + i)
 /** 兜底模型列表（接口未返回时使用，字段与 ViralVideoModel 对齐；后端返回后自动覆盖） */
 const FALLBACK_VIDEO_MODELS: ViralVideoModel[] = [
   {
@@ -2433,12 +2433,12 @@ const ViralVideoPage: React.FC = () => {
                 </div>
                 <div className="vv-form-row">
                   <label className="vv-label">文案视频时长</label>
-                  <DurationWheelPicker
+                  <Select
+                    className="vv-select"
+                    style={{ width: "100%" }}
                     value={task.duration}
-                    min={15}
-                    max={30}
-                    step={1}
                     onChange={(v) => setTask({ duration: v })}
+                    options={DURATIONS.map((n) => ({ value: n, label: `${n}秒` }))}
                   />
                 </div>
               </div>