[KanchanN-Microsoft]

Purpose

This pull request updates the Node.js version used across the development environment, Dockerfiles, and documentation for both the chat and scenario frontend applications. The main goal is to standardize on Node.js 24 LTS, ensuring consistency and compatibility throughout the project.

Node.js Version Upgrade:

• Updated the Node.js version in .devcontainer/devcontainer.json from "lts" to "24" to align the development environment with the new standard.
• Changed the base image in chat-app/frontend/Dockerfile to use nodejs:24 instead of nodejs:20.
• Changed the base images in scenario-app/frontend/Dockerfile for both widget-builder and app-builder stages to use nodejs:24 instead of nodejs:20.

Documentation Updates:

• Updated the prerequisites in chat-app/frontend/README.md to specify Node.js 24 LTS.
• Updated the prerequisites in scenario-app/frontend/README.md to specify Node.js 24 LTS.

Does this introduce a breaking change?

• Yes
• No

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code

What to Check

Verify that the following are valid

• ...

Other Information

[Copilot]

🔵 Needs a closer look

No concrete defects were identified, but successful frontend container builds and devcontainer creation remain unverified for this major Node.js upgrade.

No open issues 🎉

What changed in this PR

Standardizes the development environment and frontend container builds on Node.js 24 LTS for both applications.

Changes:

• Pins the devcontainer Node.js version to 24 instead of the moving LTS alias.
• Updates all three frontend Docker build stages from Node.js 20 to 24.
• Aligns both frontend READMEs with the Node.js 24 LTS prerequisite.

File	Description
scenario-app/​frontend/​README.md	Documents Node.js 24 LTS as a prerequisite.
scenario-app/​frontend/​Dockerfile	Updates widget and application builders to Node.js 24.
chat-app/​frontend/​README.md	Documents Node.js 24 LTS as a prerequisite.
chat-app/​frontend/​Dockerfile	Updates the frontend builder to Node.js 24.
.devcontainer/​devcontainer.json	Pins the Node.js feature to version 24.

_{Review effort: Balanced}