feat: add chalkboard style and xhs-images previews

- Add chalkboard style to baoyu-xhs-images and baoyu-comic
- Update chalkboard style for article-illustrator, cover-image, infographic
- Remove tech style from baoyu-xhs-images
- Add style and layout preview screenshots for xhs-images
- Bump version to 1.9.0

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.zh.md

@@ -99,7 +99,18 @@ npx add-skill jimliu/baoyu-skills
 /baoyu-xhs-images 今日星座运势
 ```
 
-**风格**（视觉美学）：`cute`（默认）、`fresh`、`tech`、`warm`、`bold`、`minimal`、`retro`、`pop`、`notion`
+**风格**（视觉美学）：`cute`（默认）、`fresh`、`warm`、`bold`、`minimal`、`retro`、`pop`、`notion`、`chalkboard`
+
+**风格预览**：
+
+| | | |
+|:---:|:---:|:---:|
+| ![cute](./screenshots/xhs-images-styles/cute.webp) | ![fresh](./screenshots/xhs-images-styles/fresh.webp) | ![warm](./screenshots/xhs-images-styles/warm.webp) |
+| cute | fresh | warm |
+| ![bold](./screenshots/xhs-images-styles/bold.webp) | ![minimal](./screenshots/xhs-images-styles/minimal.webp) | ![retro](./screenshots/xhs-images-styles/retro.webp) |
+| bold | minimal | retro |
+| ![pop](./screenshots/xhs-images-styles/pop.webp) | ![notion](./screenshots/xhs-images-styles/notion.webp) | ![chalkboard](./screenshots/xhs-images-styles/chalkboard.webp) |
+| pop | notion | chalkboard |
 
 **布局**（信息密度）：
 | 布局 | 密度 | 适用场景 |
@@ -111,6 +122,15 @@ npx add-skill jimliu/baoyu-skills
 | `comparison` | 双栏 | 对比、优劣 |
 | `flow` | 3-6 步 | 流程、时间线 |
 
+**布局预览**：
+
+| | | |
+|:---:|:---:|:---:|
+| ![sparse](./screenshots/xhs-images-layouts/sparse.webp) | ![balanced](./screenshots/xhs-images-layouts/balanced.webp) | ![dense](./screenshots/xhs-images-layouts/dense.webp) |
+| sparse | balanced | dense |
+| ![list](./screenshots/xhs-images-layouts/list.webp) | ![comparison](./screenshots/xhs-images-layouts/comparison.webp) | ![flow](./screenshots/xhs-images-layouts/flow.webp) |
+| list | comparison | flow |
+
 #### baoyu-infographic
 
 专业信息图生成器，支持 20 种布局和 17 种视觉风格。分析内容后推荐布局×风格组合，生成可发布的信息图。