FE-1651: Keep a notification without detail a single compact line

[kube]

Summary

Before this PR, every notification carried the chrome a long error needs. #9564 gave the toaster a description column, a copy button and a close button so an AI assistant failure could be read and copied from the toast, and applied that shape to all of them. A three-second message with no detail, "Simulation complete" among them, rendered as a tall pill: title top-aligned in a column, close button beside it.

A notification without detail is a single centred line again, with no buttons, the form it had before. One that carries detail keeps the column, the copy button and the close button, and so does an error, which never dismisses itself.

Links

• Ticket FE-1651

Changes

• A notification's buttons appear only where it needs a way out

  An error stays open until dismissed and a detail is there to be read, so both keep copy and close. A plain message clears itself after three seconds.

• The toast centres its row unless it carries detail

  data-detail on the toast root drives the alignment, so a title with a description still lines up with the top of the buttons beside it.

Test coverage

• provider.test.tsx:

  A message with no detail renders no close or copy button and no data-detail; an error with detail renders both and carries the attribute.
  Queries read from each toast's own root, since the toaster is a module singleton whose toasts outlive a test.

• Built stylesheet:

  Carries align-items: center for the toast root and align-items: flex-start only under [data-detail].

How to test

• Open Petrinaut preview on Vercel
• Menu > Load example > any model
• Switch to Simulate
• Create an experiment with a couple of runs and wait for it to finish

  Expect a single-line dark toast in the bottom right, no buttons, gone after three seconds

• Ask the AI assistant something while the assistant is unreachable

  Expect the error toast to keep its wrapped title, Copy details and Close, and to stay until closed

[vercel]

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Project	Deployment	Actions	Updated
hash	Ready	Preview	Sep 9, 2026 1:59pm UTC
petrinaut	Ready	Preview	Sep 9, 2026 1:59pm UTC

2 Skipped Deployments

Project	Deployment	Actions	Updated
hashdotdesign-tokens	Ignored	Preview	Sep 9, 2026 1:59pm UTC
petrinaut-docs	Ignored	Preview	Sep 9, 2026 1:59pm UTC

[cursor]

PR Summary

Low Risk
Scoped UI change to Petrinaut notification toasts with test coverage; no auth, data, or API impact.

Overview
Plain notifications (no detail, non-error) render as a single centered line again: no close or copy controls, and they still auto-dismiss after the default duration.

Toasts that need a way out keep the action column: anything with detail gets copy + close, and error toasts always get close (even without detail) because they stay until dismissed. The toast root sets data-detail when a description is present so layout uses centered alignment by default and top-aligns content only when detail is shown.

Adds a provider test that asserts button/data-detail presence per toast type, querying each toast root to avoid interference from the module singleton toaster.

^{Reviewed by Cursor Bugbot for commit 7a7ab75. Bugbot is set up for automated code reviews on this repo. Configure here.}

[Copilot]

🟡 Changes recommended

The new detail/dismissible/data-detail logic is inconsistent when detail is an empty string, producing a “detail” layout/state without rendering the description/copy button.

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

Pull request overview

Adjusts Petrinaut’s toast notification rendering so “plain” messages (no detail) return to a compact, single-line appearance with no action buttons, while detailed and error notifications retain the expanded layout and affordances.

Changes:

• Center-align toast content by default, switching to top alignment only when the toast carries detail (via a data-detail attribute).
• Show close/copy actions only for notifications that are errors or that include detail.
• Add a unit test asserting button/attribute presence for plain vs detailed error notifications.

File summaries

File	Description
libs/@hashintel/petrinaut/src/react/notifications/toaster.tsx	Updates toast layout/alignment and conditionally renders action buttons based on presence of detail or error type.
libs/@hashintel/petrinaut/src/react/notifications/provider.test.tsx	Adds coverage for “no detail => no buttons/attribute” and “error with detail => buttons + attribute”.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite

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