inherit aws profile from active terminal session when entering "q chat"

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue

### Operating system

macOS 15.5.0 (24F74)

### Expected behaviour

When using `granted` to assume an AWS role in the CLI, q chat ignores the active AWS profile and region from the terminal session and defaults to the profile/region from the AWS config file instead.

q chat should inherit the AWS profile and region from the active terminal session (environment variables like AWS_PROFILE, AWS_REGION, etc.)

### Actual behaviour

Terminal shows active profile: AWS_PROFILE=AIX-test and AWS_REGION=eu-central-1
q chat uses Profile name: default and Region: us-east-1 instead

### Steps to reproduce

Use granted (or similar tool) to assume an AWS role.
Verify environment variables are set correctly: env | grep AWS
Start q chat
Try AWS operations - they use default profile/region instead of active session