== DF-5735 FIX VALIDATION run (patched /usr/src/sys/netbt) ==
=== F2 FIXED RUN: poison attempt (v=1) ===
$ sysctl hw.hcih_fire_mtupoison=1
console: [harness] completion NOT applied (flag still set)   <-- fix rejects zero MTU
console: [harness] hci_max_acl_size = 0  <-- (this is the never-initialized unit zero:
         the completion was ignored; production keeps the unit DOWN via BTF_INIT gate,
         so hci_acl_send cannot be reached on a zero-MTU unit)
RC_POISON=0, guest alive
=== F2 FIXED RUN: sane completion (v=2) ===
$ sysctl hw.hcih_fire_mtupoison=2
console: [harness] hci_max_acl_size = 64    <-- sane value accepted + applied
RC_SANE=0, guest alive