Closest thing to "use the whole bond from SMB" without the
ksmbd/userspace fork dilemma. `server multi channel support = yes`
was already on but the client side (macOS, Windows) needs an
explicit capability hint to actually open more than one TCP
stream — without `interfaces ... ;capability=RSS,speed=...`,
Sequoia clients negotiate a single channel and that's it.

Now advertised:
  lo         capability=DYNAMIC speed=1                (loopback)
  10.0.1.1   capability=RSS     speed=80_000_000_000   (bond40g aggregate)

Effect: Sequoia 15.4+ opens up to 32 channels per SMB3 session;
LACP layer3+4 xmit hash distributes those streams across both
40 GbE bond slaves. Expected SMB throughput improvement is 2-4×
on bulk Finder copies vs single-channel TCP, with zero feature
loss (still userspace smbd: LDAP, Spotlight, fruit, recycle, TM
all intact).

Paired with `bind interfaces only = yes` so smbd doesn't listen
on any incidental interface (the existing `hosts allow` IP filter
stays as a second layer).

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>