feat: 内测申请弹窗 + 电商功能介绍页样式优化

- 新增 BetaApplicationModal 组件，支持文本输入、单/多选、签字等交互

- 顶部通知铃铛左侧添加「内测申请」按钮（脉冲动画）

- 电商功能介绍页等比例放大，减少空白，布局更紧凑

- 右侧卡片区域放大，卡片内容清晰可见

src/api/keyServerClient.ts

@@ -475,7 +475,7 @@ function migrateLegacyWorkflowData(old: Record<string, unknown>, wrapper: Record
     description: String(wrapper.description || ""),
     source: (wrapper.source as WebCanvasWorkflow["source"]) || "blank",
     settings: {
-      model: String(isRecord(old.settings) ? old.settings.model || "Nano Banana Pro" : "Nano Banana Pro"),
+      model: String(isRecord(old.settings) ? old.settings.model || "omni-水果 Pro" : "omni-水果 Pro"),
       ratio: String(isRecord(old.settings) ? old.settings.ratio || "1:1" : "1:1"),
       duration: String(isRecord(old.settings) ? old.settings.duration || "0s" : "0s"),
       resolution: String(isRecord(old.settings) ? old.settings.resolution || "2K" : "2K"),