[FEATURE] setup-bedrock wizard should respect AWS_CONFIG_FILE and AWS_SHARED_CREDENTIALS_FILE

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The setup-bedrock interactive wizard reads AWS profiles from the hardcoded paths ~/.aws/config and ~/.aws/credentials.
Users who set AWS_CONFIG_FILE or AWS_SHARED_CREDENTIALS_FILE to non-default paths (e.g. via direnv or wrapper scripts) will not see their profiles listed in the wizard.

Proposed Solution

The wizard should resolve config/credentials file paths using the standard environment variables:

• AWS_CONFIG_FILE → falls back to ~/.aws/config
• AWS_SHARED_CREDENTIALS_FILE → falls back to ~/.aws/credentials

The UI messages (e.g. "Reading ~/.aws/config…", "Found N profiles in ~/.aws/config and ~/.aws/credentials.") should also reflect the actual paths being read.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

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