Refactored the remark plugin system significantly. Split the monolithic remark-jekyll-includes.ts into focused single-purpose plugins: remark-image-figure.ts for image-to-figure conversion, remark-info-block.ts for info callouts, and remark-directive-cleanup.ts for cleaning up unprocessed directives. This made each plugin easier to reason about and test independently.

Reworked remark-ai-content.ts to add a prompt toggle — AI content blocks now include a clickable element to show or hide the original prompt used to generate the content. Also added a plugins README documenting how each remark plugin works and where it’s used.

Fixed a Sass darken() deprecation warning and started drafting a software quality dimensions post.