Fill in the human-tools/preview page documenting how preview URLs
let users access running services in sandbox environments from
their browser. Includes how it works, web UI and API usage,
common use cases with an example workflow, and tips. Adds a
graphviz-generated SVG of the BuildAndPreview workflow with
dark mode support.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>