Reposition library as a full ATProto longform publishing toolkit:
- Add write support via StandardSitePublisher (publish/update/delete)
- Introduce federated Bluesky comments component and utilities
- Add markdown → ATProto content transformation helpers
- Add verification helpers for .well-known and link tags
- Export schemas, collections, and new utility modules

Documentation overhaul:
- Rewrite README to focus on read + write workflows
- Add publishing, comments, verification, and transformation guides
- Clarify environment variables, security notes, and workflows
- Update examples and component docs

Developer experience:
- Add Vitest and test scripts
- Export new subpaths (publisher, content, comments, verification, schemas)
- Add Zod for schema validation
- Expand keywords to reflect federation and publishing

- Add katex and shiki dependencies for LaTeX math and syntax highlighting
- Export DocumentRenderer component from library index
- Replace custom content rendering with DocumentRenderer in document page
- Apply code formatting fixes across documentation and examples

This introduces proper rich text rendering capabilities including:
- Math equations via KaTeX
- Syntax highlighting via Shiki
- Headers, lists, blockquotes with theme support
- Links, mentions, and inline formatting

Breaking changes: None - this is additive functionality

- Rewrite API.md and EXAMPLES.md with a new structure and more comprehensive guides.
- Introduce a themed component system including StandardSiteLayout, ThemedCard, and ThemeToggle.
- Add themeStore and theme utilities for managing light/dark modes and dynamic CSS variables.
- Update DocumentCard and PublicationCard to support themes and Lucide icons.
- Add @lucide/svelte as a dependency for enhanced UI elements.
- Export new style entry points for base and theme CSS.