feat: Add multiplatform Docker support (ARM64 + AMD64)

[manavgup]

🚀 Multiplatform Docker Support

This PR implements multiplatform Docker image builds supporting both AMD64 and ARM64 architectures.

Changes Made:

• ✅ Updated Containerfile.lite for ARM64 compatibility
• ✅ Modified GitHub Actions workflows for multiplatform builds
• ✅ Enhanced Makefile with multiplatform build targets
• ✅ Added comprehensive testing and documentation

Key Features:

• 🏗️ Multi-platform builds: linux/amd64,linux/arm64
• 🔧 ARM64 compatibility: Fixed shell and package manager issues
• 🚀 CI/CD integration: Updated all Docker build workflows
• 📚 Documentation: Added comprehensive testing guide

Testing:

• ✅ Local ARM64 build tested successfully
• ✅ FastAPI application loads correctly
• ✅ All dependencies properly installed
• ✅ GitHub Actions workflow syntax validated

Addresses:

• Closes #80
• Addresses PR #322

Ready for Review:

All multiplatform Docker functionality has been tested and is ready for production deployment.