feat: restructure gen2D deck with enriched content and frankfurt theme components

- Restructure from 12 slides to 21 slides with proper section navigation
- Split into pages/ for modular maintenance (15 page files)
- Use frankfurt theme: cover layout, Item component, section frontmatter
- Remove all two-cols layouts to avoid rendering issues
- Add rich content from tmp/ docs: Eino pipeline, prompt agent, async tasks, data model, deployment
- Use Item component for structured content blocks
- Add mermaid ER diagram for data model
- Add Go code block for pipeline type definitions

decks/gen2D/pages/dedup-ws.md

@@ -0,0 +1,32 @@
+# 请求去重 + 实时推送
+
+两项关键的工程优化
+
+<Item title="🔍 请求去重（Request Dedup）">
+
+- **策略**：`hash(prompt + assetType + params)` 生成唯一键
+- **存储**：`sync.Map` 内存缓存，TTL 自动过期
+- **逻辑**：相同参数的并发请求自动合并，返回已有 `taskId`
+- **效果**：避免重复生成，节省 API 调用成本，提升用户体验
+
+</Item>
+
+<Item title="📡 WebSocket 实时推送">
+
+- 用户建立 `ws://host/api/v1/tasks/:taskId/ws` 连接
+- 管线各阶段执行时推送实时状态消息：
+
+```json
+{
+  "type": "progress",
+  "stage": "asset_generator",
+  "progress": 45,
+  "message": "正在生成素材..."
+}
+```
+
+- 质检重试时推送额外信息：重试次数、重试原因
+- 管线完成时推送最终结果：素材 URL、元数据
+- **兼容方案**：同时支持 HTTP 轮询（`GET /api/v1/tasks/:taskId`）
+
+</Item>