feat: add models endpoint querying to agentic engine JS harness (all engines)#28579

Copilot wants to merge 5 commits into

maingithub/gh-aw:mainfrom

copilot/update-agentic-engine-models-endpointgithub/gh-aw:copilot/update-agentic-engine-models-endpointCopy head branch name to clipboard