feat: Finalize production-ready cover image implementation

- Update documentation with comprehensive size handling guidelines
- Configure Jekyll to exclude agent markdown files from build process
- Add case-insensitive exclusions for claude.md, warp.md, agent.md variants
- Remove test files and ensure clean production state
- Update GitHub Copilot instructions with production guidelines
- Cover images now fully responsive and production-tested

Features:
- Automatic responsive scaling (400px desktop, 250px tablet, 200px mobile)
- Support for SVG (preferred), PNG, JPG formats
- Graceful handling of posts without cover images
- Minimal performance impact (2.3KB typical SVG)
- Comprehensive testing across all device sizes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: solrevdev

.github/copilot-instructions.md

@@ -18,9 +18,11 @@ This is a Jekyll-based static blog for solrevdev.com using the Hyde theme with c
 ### Cover Images
 - Store in `/images/` directory
 - Use `cover_image: /images/filename.ext` in front matter
-- Supported formats: SVG (preferred), PNG, JPG
-- Recommended dimensions: 800x400px
-- Automatically responsive across desktop, tablet, and mobile
+- Supported formats: SVG (preferred), PNG, JPG - all handled gracefully
+- Size handling: CSS automatically scales images responsively
+- Recommended dimensions: 800x400px aspect ratio
+- Keep file size under 50KB for performance
+- Optional field - posts without cover images work perfectly
 
 ### Local Development Image Issues
 **Important**: During local development, images may not display properly due to URL resolution:
@@ -52,6 +54,6 @@ This is a Jekyll-based static blog for solrevdev.com using the Hyde theme with c
 ```
 
 ### Testing
-- Use `test-cover-image.html` for image URL testing
 - Test responsive design at 375px (mobile), 768px (tablet), 1200px+ (desktop)
-- Screenshots saved in `.playwright-mcp/` directory
+- Cover images scale automatically across all device sizes
+- Posts without cover images display normally

_config.yml

@@ -46,7 +46,7 @@ version: "2.1.0"
 
 github: [metadata]
 
-exclude: ["Rakefile", "vendor"]
+exclude: ["Rakefile", "vendor", "claude.md", "CLAUDE.md", "warp.md", "WARP.md", "agent.md", "AGENT.md", "agents.md", "AGENTS.md"]
 
 # Social Sharing
 facebook_app_id: "1213637668669023"

claude.md

@@ -34,7 +34,19 @@ For local development, either:
 - Mobile-specific margin adjustments for better display
 
 ### Cover Image Guidelines
-- Use SVG format for scalable graphics where possible
-- Recommended dimensions: 800x400px for optimal display
-- Include descriptive alt text for accessibility
-- Store images in `/images/` directory
+- **Supported formats**: SVG (preferred), PNG, JPG - all handled gracefully by CSS
+- **Size handling**: CSS automatically scales images responsively:
+  - Desktop: max-height 400px
+  - Tablet: max-height 250px
+  - Mobile: max-height 200px
+- **Recommended dimensions**: 800x400px aspect ratio for optimal display
+- **File size**: Keep under 50KB for performance (SVG typically 2-5KB)
+- **Alt text**: Automatically uses page title for accessibility
+- **Storage**: Place images in `/images/` directory
+
+### Testing Results (Production Ready)
+- ✅ Images scale gracefully across all device sizes
+- ✅ Posts without cover images display normally
+- ✅ Performance impact minimal (2.3KB SVG)
+- ✅ All image formats (SVG, PNG, JPG) supported
+- ✅ Responsive breakpoints working properly