`--authorizer-type AWS_IAM` rejected by `agentcore add gateway` but selectable in interactive TUI

[alvarog2491]

Description

agentcore add gateway --authorizer-type AWS_IAM fails with a validation error, but the same value can be selected successfully through the interactive TUI (agentcore add → Gateway → AWS IAM). The two flows are inconsistent.

Steps to Reproduce

Interactive TUI (works):

agentcore add
# Select "Gateway" → select "AWS IAM" as authorizer type → gateway created successfully

Non-interactive CLI flag (fails):

agentcore add gateway --name my-gateway --authorizer-type AWS_IAM

Error output:

Invalid authorizer type. Use NONE or CUSTOM_JWT

Expected Behavior

--authorizer-type AWS_IAM should be accepted by the CLI flag, matching what the interactive TUI allows.

Actual Behavior

The CLI flag rejects AWS_IAM with a validation error. Only NONE and CUSTOM_JWT are accepted.

CLI Version

0.8.0

Operating System

macOS

Additional Context

No response