FE-1500: switch the example embed to the Petrinaut preview

[kube]

Summary

Before this PR, /embed/examples/<slug> mounted the full read-only Petrinaut component. Every embed loaded Monaco and the language server to show a model, and offered no way to run it.

The route switches to PetrinautPreview with Quick Simulation. The compact surface loads no language tooling and runs the model's named scenarios from build-time artifacts. The embed URL contract does not change.

9448.mp4

Links

• Ticket FE-1500

Changes

• EmbeddedExamplePage lazy-loads PetrinautPreview from @hashintel/petrinaut/preview

  quickSimulation comes from the build-time HIR artifacts via loadExampleRuntime plus the catalog's parameter bounds.
  Step size and horizon use the simulation defaults.

• Embed route loads the runtime artifacts alongside the model

  Loader resolves loadExample and loadExampleRuntime together.
  Navigation applies applyPreviewNavigationUpdate to the previous search, so the URL carries the same shared subset through the preview-typed codec.

• validateSharedExampleSearch stays the route's search contract

  A fast-check property asserts the preview codec produces the same search as the shared codec on every generated input, so existing embed URLs keep working.

Test coverage

• example-search.property.test.ts:

  Preview-codec laws, including the codec-equivalence property that pins the URL contract across the switch.

• navigation-search.test.ts, example-search.test.ts:

  Existing shared codec laws, unchanged.

How to test

Embed on the Preview

• Open Petrinaut /embed/examples/gases-1-pn on Vercel

  Expect compact preview instead of full editor

• Quick Simulation > Play

  Expect run to advance with the timeline

URL contract unchanged

• Open a scenario, subnet, or itemType and itemId URL from the previous embed

  Expect it to resolve identically

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
hash	Ready	Preview	Sep 5, 2026 4:30pm UTC
petrinaut	Ready	Preview	Sep 5, 2026 4:30pm UTC
petrinaut-docs	Ready	Preview	Sep 5, 2026 4:30pm UTC

1 Skipped Deployment

Project	Deployment	Actions	Updated
hashdotdesign-tokens	Ignored	Preview	Sep 5, 2026 4:30pm UTC

[semgrep-code-hashintel]

Semgrep found 4 detect-replaceall-sanitization findings:

• apps/petrinaut-website/api/oembed.ts
  • L87-92 - Triage
  • L87-91 - Triage
  • L87-89 - Triage
  • L87-88 - Triage

Detected a call to replaceAll() in an attempt to HTML escape the string value .replaceAll("&", "&amp;") .replaceAll('"', "&quot;") .replaceAll("'", "&#39;") .replaceAll("<", "&lt;"). Manually sanitizing input through a manually built list can be circumvented in many situations, and it's better to use a well known sanitization library such as sanitize-html or DOMPurify.

Semgrep found 1 regex_dos finding:

• apps/petrinaut-website/src/main/app/brunch-demo/brunch-endpoint.ts
  • L8-18 - Triage

Ensure that the regex used to compare with user supplied input is safe from regular expression denial of service.

[cursor]

PR Summary

Medium Risk
Embed behavior and loader/navigation wiring change in a public iframe surface, though URL compatibility is explicitly property-tested against the prior shared search codec.

Overview
/embed/examples/<slug> no longer mounts the full read-only Petrinaut editor (Monaco + language server). It lazy-loads PetrinautPreview with Quick Simulation, driven by build-time HIR runtime artifacts and catalog parameter bounds, while default step size and horizon stay on simulation defaults.

The embed route loader now resolves the model and runtime together (loadExample + loadExampleRuntime). URL navigation uses the preview navigation path (applyPreviewNavigationUpdate) so the same shared query subset still flows through the address bar. validateSharedExampleSearch remains the route’s search contract; a fast-check property asserts preview-codec decoding matches the shared codec so existing scenario / subnet / itemType / itemId embed URLs keep working.

^{Reviewed by Cursor Bugbot for commit 1436c2d. Bugbot is set up for automated code reviews on this repo. Configure here.}

[Copilot]

🟡 Changes recommended

Preview navigation currently removes supported mode, view, and overlay URL parameters.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Switches example embeds from the full editor to the lightweight Petrinaut Preview with Quick Simulation.

Changes:

• Loads model and runtime artifacts concurrently.
• Adapts shared URL navigation to Preview state.
• Adds property-based codec coverage.

File summaries

File	Description
embed.examples.$slug.tsx	Loads runtime artifacts and wires Preview navigation.
navigation-search.ts	Adds Preview search conversion helpers.
example-search.property.test.ts	Tests Preview codec behavior.
embedded-example-page.tsx	Renders PetrinautPreview with Quick Simulation.

Review details

• Files reviewed: 4/4 changed files
• Comments generated: 1
• Review effort level: Balanced

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[kube]

Not actually merged. A bad rebase from my side briefly pushed this branch at its own base, so GitHub saw no commits between them, marked the PR merged and deleted the branch. Nothing landed in `main`. The branch is restored with its commit and the work continues in #9547.