KMV-9: GitHub Actions

[WiolaWysopal]

Description

This PR introduces a complete Continuous Integration (CI) pipeline using GitHub Actions for the KMeans Visualizer project.

The workflow automatically validates code quality, verifies application builds, validates infrastructure configuration, and ensures project consistency on every push and pull request.

Changes

• Added GitHub Actions CI workflow configuration
• Implemented automated backend quality checks using Ruff and Black
• Implemented automated frontend linting using ESLint
• Implemented automated frontend production build verification
• Added automated backend Docker image build validation
• Added automated frontend Docker image build validation
• Implemented Kubernetes manifest validation
• Updated project documentation with CI workflow information
• Updated project structure documentation to include GitHub Actions configuration

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Testing

• Application builds successfully
• Manual testing completed
• API endpoints verified (if applicable)

Checklist

• Code follows project style guidelines
• Self-review completed
• Documentation updated
• No breaking changes