v12.0.0-beta.6

Merged

• Bump mermaid from 11.17.2 to 12.0.0 #324
• Add type-only layout registry for inferred chain contracts #318
• Add page outputs from page modules, vars companions, and layouts #323
• Test and document SharedWorker support #317

Commits

• Simplify additional outputs to direct writes and duplicate warnings 534210b
• Detect conflicting output paths across build steps (#288 foundation) bd22a2b
• Add page-owned additional outputs from page and layout hooks d53fedf