Device binding on attach is fully wired with detailed outcomes, but its enable predicate is decided outside the source.
Attaching to a remote session now checks first whether that session is bound to one device, and registers only when egress is available, an account uuid is present and the local device id matches. Every outcome is reported as tengu_device_bind_attach with a result such as bound, egress, account, no_device_here, other_device, session_unbound or session_unreadable. The whole check sits behind an enable predicate; when it is false or throws, the result is disabled. Nothing in the build sets that predicate's effective value, so it is decided outside the source.
Strings lifted out of the shipped bundle, so the claim above can be checked against them.