Add Terraform Infrastructure as Code Setup

[DJSaunders1997]

This PR adds a complete Terraform configuration for managing the GPTeasers Azure Container Apps infrastructure.

Changes Added

• Terraform Configuration: Complete IaC setup for Resource Group, Container App Environment, and Container App
• Secure Secrets Management: Variables for all API keys (OpenAI, Azure AI, Gemini, DeepSeek) with proper lifecycle management
• Documentation: Comprehensive README with deployment instructions and troubleshooting
• Security: Updated .gitignore to exclude terraform state files and sensitive variables
• Organization: Moved terraform directory under backend/ for better project structure

Key Features

• Automated infrastructure provisioning and management
• Secure handling of API keys and tokens
• Infrastructure visualization with GraphViz
• CI/CD friendly configuration with image update flexibility

Future Enhancements

I might come back to this in the future to parameterize the container image reference for dynamic deployments, enabling:

• Automated image updates from CI/CD pipelines
• Blue/green deployment strategies
• Version-controlled infrastructure changes

For now, this provides a solid foundation for infrastructure management and serves as safe keeping for future IaC improvements.

[cr-gpt]

Code Review:

1. Correctness:

   • The added Terraform-related entries seem appropriate for ignoring sensitive Terraform files (terraform.tfvars, terraform.tfstate*, .terraform/).
   • No obvious bugs in handling the new additions.

2. Improvements:

   • Consider adding comments explaining each ignore pattern to enhance readability.
   • It's a good practice to sort the patterns alphabetically; it helps maintain a consistent style and makes it easier to locate specific entries.
   • Ensure that these patterns accurately reflect what should be ignored by version control.

3. Risk Assessment:

   • Depending on the project, ensure that the .tfstate is managed securely as it can contain sensitive information.
   • Regularly review and update these ignore patterns as your project evolves to ensure that nothing essential is being inadvertently omitted.

Overall:

The changes made appear to address the necessary additions for Terraform file management. Adding comments and sorting the entries would be helpful for code maintenance. Regularly reviewing these ignore lists is important to maintain security and prevent accidental exposure of sensitive information.