Dev container for AutoGen Studio

[JohanForngren]

What feature would you like to be added?

Add a dev container configuration for AutoGen Studio to enable consistent development environments. The dev container should include:

• Python environment with core dependencies for AutoGen Studio development
• Node.js and npm for the frontend stack
• Pre-configured development tools and settings
• Optionally: Recommended vscode plugins

Why is this needed?

A dev container would streamline contributor onboarding and eliminate environment inconsistencies, reducing setup friction and "works on my machine" issues. This is crucial for AutoGen Studio's Python/React architecture that requires multiple runtime environments.