fix: trim gen2D slide content to prevent overflow beyond header/footer

- Reduce Item count per slide: pipeline 4→3, solution 4→2, highlights 6→4
- Remove tech-stack architecture layering Item (moved to tech-stack grid)
- Simplify eino-graph: shorter Go code, 3 Items→2
- Simplify prompt-agent: smaller mermaid, shorter Item text
- Simplify async-task: merge 3 Items→2, remove footer
- Simplify data-model: merge 4 grid items→2
- Simplify architecture: reduce ASCII diagram from 38 to 20 lines
- Simplify dedup-ws: remove JSON code block, shorter Items
- Simplify deployment: smaller mermaid, shorter Items
- Simplify problem: shorter Item text, remove bullet lists
- Simplify style-system: fix typo, shorter Item text

decks/gen2D/pages/data-model.md

@@ -2,7 +2,7 @@
 
 四表结构，清晰的实体关系
 
-```mermaid {scale: 0.8}
+```mermaid {scale: 0.7}
 erDiagram
     USER ||--o{ PROJECT : "拥有"
     PROJECT ||--|| PROJECT_STYLE : "配置"
@@ -12,28 +12,15 @@ erDiagram
 
 <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 title="👤 USER + PROJECT">
+- 用户：`id`(base62)、`username`、`password_hash`(bcrypt)
+- 工程：`id`、`user_id`、`name`、`description`
 </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 title="🎨 STYLE + TASK + ASSET">
+- 风格表：`project_id` 一对一，`kv_pairs` JSON 存储
+- 任务：`prompt`、`status`、`style_override`
+- 素材：`file_url`、`metadata`，存于七牛云 Kodo
 </Item>
 
 </div>