Feat: Avoid hardcoding AWS credentials & support standard AWS env variables

[chandrashekhar07]

Problem:
Currently, the application requires AWS credentials (AWS_ACCESS_KEY and AWS_SECRET_KEY) to be passed explicitly as plain environment variables. This creates a few issues:

Hardcoding credentials is insecure and discouraged by AWS best practices

In self-hosted or cloud-native environments (EKS, ECS, EC2, etc.), IAM roles / service accounts are commonly used instead of static credentials

Also, the variable names do not follow AWS-standard conventions, which can cause confusion and reduce compatibility with existing tooling

Proposal:

• Make AWS credentials optional: Allow the application to run without explicitly setting AWS access keys. Rely on AWS SDK’s default credential provider chain (IAM role, service account, instance profile, etc.) when credentials are not provided

• Support standard AWS environment variable names:
  Replace non-standard keys with AWS-supported naming:

AWS_ACCESS_KEY_ID="your-access-key"
AWS_SECRET_ACCESS_KEY="your-secret-key"