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/data-model.md

@@ -0,0 +1,39 @@
+# 数据模型与存储
+
+四表结构，清晰的实体关系
+
+```mermaid {scale: 0.8}
+erDiagram
+    USER ||--o{ PROJECT : "拥有"
+    PROJECT ||--|| PROJECT_STYLE : "配置"
+    PROJECT ||--o{ TASK : "生成"
+    TASK ||--o{ ASSET : "产出"
+```
+
+<div class="grid grid-cols-2 gap-4 mt-2">
+
+<Item title="👤 USER 用户表">
+- `id`：前缀 + 随机 base62（6 字节 crypto/rand）
+- `username`：唯一用户名
+- `password_hash`：bcrypt 哈希
+</Item>
+
+<Item title="📁 PROJECT 工程表">
+- `id`：唯一标识
+- `user_id`：外键关联用户
+- `name` / `description`：工程信息
+</Item>
+
+<Item title="🎨 PROJECT_STYLE 风格表">
+- `project_id`：一对一关联工程
+- `kv_pairs`：JSON 存储风格键值对
+- 支持 `custom:` 前缀自定义标签
+</Item>
+
+<Item title="📦 TASK + ASSET 任务/素材表">
+- Task：`id` / `project_id` / `prompt` / `status` / `style_override`
+- Asset：`id` / `task_id` / `file_url` / `metadata`
+- 文件存储：七牛云 Kodo，CDN 签名访问
+</Item>
+
+</div>