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>

skills/baoyu-article-illustrator/references/styles/chalkboard.md

@@ -1,56 +1,60 @@
 # chalkboard
 
-Classic classroom chalkboard style for educational content
+Black chalkboard background with colorful chalk drawing style
 
 ## Design Aesthetic
 
-Classic classroom chalkboard aesthetic with hand-drawn chalk illustrations. Nostalgic educational feel with imperfect, sketchy lines. Colorful chalk creates visual hierarchy while maintaining authentic chalkboard warmth.
+Classic classroom chalkboard aesthetic with hand-drawn chalk illustrations. Nostalgic educational feel with imperfect, sketchy lines that capture the warmth of traditional teaching. Colorful chalk creates visual hierarchy while maintaining the authentic chalkboard experience.
 
 ## Background
 
 - Color: Chalkboard Black (#1A1A1A) or Dark Green-Black (#1C2B1C)
-- Texture: Realistic chalkboard texture with dust and eraser marks
+- Texture: Realistic chalkboard texture with subtle scratches, dust particles, and faint eraser marks
+
+## Typography
+
+Hand-drawn chalk lettering style with visible chalk texture. Imperfect baseline adds authenticity. White or bright colored chalk for emphasis.
 
 ## Color Palette
 
 | Role | Color | Hex | Usage |
 |------|-------|-----|-------|
 | Background | Chalkboard Black | #1A1A1A | Primary background |
-| Alt Background | Green-Black | #1C2B1C | Traditional green |
-| Primary | Chalk White | #F5F5F5 | Main elements |
-| Accent 1 | Chalk Yellow | #FFE566 | Highlights |
+| Alt Background | Green-Black | #1C2B1C | Traditional green board |
+| Primary Text | Chalk White | #F5F5F5 | Main text, outlines |
+| Accent 1 | Chalk Yellow | #FFE566 | Highlights, emphasis |
 | Accent 2 | Chalk Pink | #FF9999 | Secondary highlights |
 | Accent 3 | Chalk Blue | #66B3FF | Diagrams, links |
-| Accent 4 | Chalk Green | #90EE90 | Success, growth |
+| Accent 4 | Chalk Green | #90EE90 | Success, nature |
 | Accent 5 | Chalk Orange | #FFB366 | Warnings, energy |
 
 ## Visual Elements
 
-- Hand-drawn chalk illustrations
-- Chalk dust effects
-- Doodles: stars, arrows, underlines
-- Mathematical formulas
-- Eraser smudges and chalk residue
-- Stick figures and icons
-- Connection lines with hand feel
-- Checkmarks and annotations
+- Hand-drawn chalk illustrations with sketchy, imperfect lines
+- Chalk dust effects around text and key elements
+- Doodles: stars, arrows, underlines, circles, checkmarks
+- Mathematical formulas and simple diagrams
+- Eraser smudges and chalk residue textures
+- Wooden frame border optional
+- Stick figures and simple icons
+- Connection lines with hand-drawn feel
 
 ## Style Rules
 
 ### Do
 
-- Maintain chalk texture on all elements
-- Use imperfect hand-drawn quality
-- Add chalk dust and smudge effects
-- Create hierarchy with color
-- Include playful annotations
+- Maintain authentic chalk texture on all elements
+- Use imperfect, hand-drawn quality throughout
+- Add subtle chalk dust and smudge effects
+- Create visual hierarchy with color variety
+- Include playful doodles and annotations
 
 ### Don't
 
 - Use perfect geometric shapes
-- Create clean digital lines
+- Create clean digital-looking lines
 - Add photorealistic elements
-- Use gradients or gloss
+- Use gradients or glossy effects
 - Make it look computerized
 
 ## Best For