Document recommended pattern for role/identity propagation in MCP tool execution #2634

Job	Run time
build (macos-latest, Release)	6m 11s
build (windows-latest, Debug)	12m 2s
build (macos-latest, Debug)	6m 1s
build (ubuntu-latest, Release)	7m 1s
build (windows-latest, Release)	11m 51s
build (ubuntu-latest, Debug)	7m 5s
publish-coverage / publish-coverage	57s
	51m 8s

Provide feedback