6.0.0-RC6

refactor(token): Use Horde\Token\Token directly at four sites
fix: Observability endpoint is a middleware, not a controller
refactor: port session admin screen to new SessionAdministrator helper
refactor(cli): Port horde-active-sessions to SessionAdministrator
refactor(cli): Port horde-sessions-gc to modern SessionHandler
refactor: Make AuthCredentialStore mandatory
fix(auth): Read credentials via AuthCredentialStore in JWT issuance
refactor(diagnostic): Port session inspection to the modern stack
refactor(application): Port logout gc_tempfiles loop to HordeSession
refactor(auth): Port JWT bootstrap flash data to HordeSession
refactor(base): admin/hashtable.php uses Horde\HashTable\HashTable