feat: complete attribute-first Blueprint rendering

[ejgallego]

This PR makes declarations tagged with @[blueprint] a first-class Manual authoring source and completes the rendered attribute-first workflow.

• Add source-ordered module inclusion and qualified declaration-name defaults for bare @[blueprint].
• Preserve structural doc.verso content, including math, in statements and Lean declaration panels.
• Apply consumer-side code folding consistently and cover declaration data, traversal, generated HTML, and browser hydration.

Thanks to Lua Viana Reis for valuable feedback on the attribute-first authoring workflow.

Backport v4.32.0: #359