logout: end-to-end test pinning the --all/--everywhere matrix

Runs the real cobra logout command against two fake entire-core servers and asserts which revoke shape each context's core receives across all four quadrants: logout → active context, current session logout --everywhere → active context, all sessions logout --all → every context, current session each logout --all --everywhere → every context, all sessions each

This pins the command-layer mapping (--everywhere → revoke-all per core) that the runLogout/runLogoutAll unit tests can't reach, since they inject the revoke func directly.