feat: add Pi agent blog post, AI tooling, and SVG support

Add new blog post documenting a week using the Pi CLI agent for 100% agentic development. Include AI agent configuration with custom prompts and skills to streamline content creation workflow.

- Publish "Week with my-pi-agent" article with Pi logo and screenshot assets
- Add .pi/ configuration with new-blog-post prompt and review-article skill
- Create AGENTS.md with comprehensive project documentation for AI assistants
- Fix SVG rendering to skip unsupported dimension extraction in markdown filter
- Update picture generator to handle SVG files with simple img tag
- Update syntect dependency to 5.3.0 with default-fancy features
- Swap featured segment from older post to new Pi agent article

Cargo.toml

@@ -22,7 +22,7 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 image = "0.25.6"
 anyhow = "1.0.86"
 rayon = "1.10.0"
-syntect = "5.2.0"
+syntect = { version = "5.3.0", default-features = false, features = ["default-fancy"] }
 indoc = "2.0.5"
 askama_escape = "0.15.0"
 mime_guess = "2.0.5"