A scratch pad for temporary DoenetML editing

[dqnykamp]

This PR adds a scratch pad where one explore DoenetML in an editor even without being logged in.

Edits to the scratch pad are saved to local storage (and erased if one is logged in and then logs out). If one loads new DoenetML into the scratch pad, previous work in the scratch pad is erased. One can load in sample content from the scratch pad, and one can load activities DoenetML into the scratch pad from the activity viewer page.

[Copilot]

Pull request overview

This PR introduces a Scratch Pad feature that allows users to experiment with DoenetML editing in a temporary, non-persistent workspace. Users can load example documents, edit DoenetML code, and optionally load existing content into the scratch pad for experimentation.

Key changes:

• Added a new /scratchPad route with a full-featured DoenetML editor that uses localStorage for temporary storage
• Introduced server-side support for retrieving the default DoenetML version via a new API endpoint
• Added the ability to load documents into the Scratch Pad from the content menu, with restrictions for non-default DoenetML versions

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
server/src/types.ts	Added optional doenetmlVersion field to ContentDescription type
server/src/query/activity.ts	Extracted getDefaultDoenetmlVersion function and refactored existing code to use it
server/src/routes/infoRoutes.ts	Added /getDefaultDoenetmlVersion endpoint to expose default version info
server/src/test/activity.test.ts	Added test coverage for the new getDefaultDoenetmlVersion function
client/src/types.ts	Mirrored server-side type change for ContentDescription
client/src/paths/ScratchPad.tsx	Implemented main Scratch Pad component with DoenetML editor, example loading, and localStorage persistence
client/src/popups/AddContentToMenu.tsx	Added "Load into Scratch Pad" menu item with version compatibility checking
client/src/paths/SiteHeader.tsx	Added localStorage cleanup on logout to clear scratch pad data
client/src/paths/Home.tsx	Added promotional link to Scratch Pad on homepage
client/src/index.tsx	Registered Scratch Pad route in the application router
client/src/assets/scratchPadDefault.doenet	Welcome content with basic DoenetML examples
client/src/assets/multipleChoiceExamples.doenet	Comprehensive multiple-choice answer examples
client/src/assets/mathAnswerExamples.doenet	Mathematical answer component examples
client/src/assets/graphicalAnswerExamples.doenet	Graphical interaction and answer examples
client/package.json	Expanded wireit build file patterns to include TSX, JSX, and CSS files; removed .env.production reference

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.