Iframes | Allow clipboard copy and paste from simulations

[BrianGenisio]

Summary

Side-content iframes (simulation, markdown reference, and external URL) can use the clipboard, so copy and paste inside a sim works.

Changes

Permissions Policy does not grant clipboard to iframes by default. .activity-content-iframe now sets allow="clipboard-read; clipboard-write".

The examples picker wraps /play in #app-frame. Nested iframes only get clipboard if every ancestor delegates it, so the picker iframe gets the same allow list.

Test plan

• npm run examples, pick a /sim/ example, copy text from the simulation panel and paste it into a blank or text input
• Same check on /play without the picker (npm start with a sim question.md)

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 01f8c840-ab96-470b-b616-45d35e64ee1d

📥 Commits

Reviewing files that changed from the base of the PR and between f375995 and a948b75.

📒 Files selected for processing (2)

• public/examples-mode.html
• public/utils/activity-content-shell.js

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📝 Walkthrough

Walkthrough

The preview iframe in public/examples-mode.html and the activity content iframe in public/utils/activity-content-shell.js now declare clipboard-read and clipboard-write permissions through the allow attribute. The preview iframe retains its /play source.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: enabling clipboard copy and paste in simulation iframes.
Description check	✅ Passed	The description accurately explains the clipboard permissions, affected iframes, nested iframe behavior, and test plan.

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