What is this PR for?

This PR removes the unused 'server' module and updates the project to use the 'demo' module instead.

Overview or reasons

• Removed the no longer used 'server' module from the project configuration
• run-server.sh was still referencing the old 'server' module, causing it to fail to run properly

Tasks

• Removed 'server' module from settings.gradle
• Updated run-server.sh to reference the 'demo' module

Result

• Running run-server.sh now starts the 'demo' module
• Project structure is simplified by removing the unused 'server' module