PR to fix AWS Bedrock auth for CLI when using IAM credentials (no API key needed). Fixes the case where

--override-with-envs

would bail on missing

LLM_API_KEY

for Bedrock/SageMaker models. Ready for review + merge since I can't merge after approval https://github.com/OpenHands/OpenHands-CLI/pull/612

CC @average-processor-75195 I think this came up recently - so fyi! Thanks Aman!