Iteration 2: Getting all simple code listings working

[Joshua-Lester3]

Description

Describe your changes here.

Fixes #Issue_Number (if available)

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• Code compilation
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

[Copilot]

Pull request overview

Updates the TryDotNet front-end integration to support running a broader set of code listings by (a) curating which listings get “Run” buttons and (b) adjusting how listing code is classified and prepared before execution.

Changes:

• Add support for loading a curated runnable-listings set from chapter-listings.json and only injecting Run buttons for those listings.
• Update “complete program” detection logic and change how listing code is pre-processed (region stripping / optional usings).
• Adjust TryDotNet session initialization parameters for the opened document.

Comments suppressed due to low confidence (1)

EssentialCSharp.Web/wwwroot/js/trydotnet-module.js:148

• createScaffolding() no longer includes any using directives, and the current flow does not call prependUsings() for scaffolded code. This will cause scaffolded snippets that rely on SDK implicit/global usings (e.g., Console, List<T>) to fail to compile under TryDotNet's console package. Either put the required usings back into the scaffolding template or ensure the generated fileContent (both complete and scaffolded) is passed through prependUsings() when needed.

function createScaffolding(userCode) {
    return `
namespace Program
{
    class Program
    {
        static void Main(string[] args)
        {
            #region controller
${userCode}
            #endregion
        }
    }
}`;