Fix crash caused by editor

[pearmini]

close #170

@ChloeYanYan She reported the following code crashes the browser and no way to open the notebook:

let height = 5;
let triangle = '';

for (let i = 1; i <= height; i++) {
  triangle += ' '.repeat(height - i); 
  triangle += '*'.repeat(i * 2 - 1); 
  triangle += '\n';
}

echo(triangle);

This is because we don't handle top-level non function statement correctly, such as for statement. This PR introduces a way to fix it.

Also, in oder to prevent crashing the browser because of editor, we'll unexpected error and ask users to open console for details by alerts.

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
recho-notebook	Ready	Preview	Comment	Oct 17, 2025 8:42pm

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[Copilot]

Pull Request Overview

Fixes a browser crash when executing top-level non-function statements (e.g., for loops) by making evaluation resilient and surfacing errors to users without breaking the editor.

• Add safeEval fallback to wrap non-function code in a function
• Add editor-level error handling with a debounced alert and wire it through createEditor
• Add tests for special statements and minor link/navigation fixes

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
runtime/index.js	Adds try/catch and wraps non-function code in a function before evaluation.
editor/index.js	Accepts onError and wraps run() in try/catch to surface errors.
app/Editor.jsx	Introduces a debounced default onError (alert) and passes onError to the editor.
app/SafeLink.jsx	Removes redundant preventDefault in SafeLink click handler.
app/Nav.jsx	Uses a plain anchor for external navigation to recho.dev.
test/js/special-statement.js	Adds code sample exercising top-level for/if statements.
test/js/index.js	Exports specialStatement test input.
test/js/index-tests.js	Exports specialStatement tests.
test/output/specialStatement.js	Adds expected output fixture for special statement behavior.

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