hub v0.66.0 + ISO v1.20.0: customer self-bind (R-27 slice 1)

Let a customer bind their own freshly-installed appliance without the
operator: operator "Send self-bind link" mints a 7-day tokenized
capability link, emailed (Hungarian, sibling sender) to the customer, who
opens a public /bind/<token> page and proves two factors — the console
pairing code shown on the box screen + their retrieval passphrase — and
the hub stages the bind via the same BindAppliance (provenance
customer_selfbind). The box's ~30s appliance poll delivers.

Viktor's three rulings verbatim: console pairing code (no appliance list
ever rendered), operator-sent tokenized link, 5-attempt lockout ->
"call support". Wrong code == wrong passphrase (one generic failure, no
oracle, both factors compared unconditionally); expiry falls back to
operator-bind unchanged.

THE TRAP: one public prefix /bind/, exempt from auth+CSRF at both /login
gate sites via a single isPublicBindPath predicate (tight trailing-slash
match; ServeMux ..-cleans; handler rejects '/' in token). 9 tests
(Scenarios A-F + F1/F2); 4 red-proofs verified red-then-green (lockout,
oracle, widened-prefix, single-active). GC verdict: no appliance GC ->
the 7-day TTL stands alone. Controller/agent untouched; R-27b deferred.

Green: full hub build/vet/test (17 ok) + bash -n + hub confirm gate.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017qDiBqKKQ5vPB5fXBqu7Kp

hub/internal/web/appliances_test.go

@@ -17,7 +17,7 @@ func seedAppliance(t *testing.T, st *store.Store, uuid, macSet string) int64 {
 	// a real ed25519 host key line so the fingerprint helper has something to parse
 	sshKey := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHVBv+9slP74+1/vNhiI0OJDrXQ2nvb8iwmIxMfUZn36 host"
 	hw := `{"product":"Intel N100 mini","cpu":"Intel(R) N100","mem_kb":16150372}`
-	if _, err := st.RegisterAppliance(uuid, macSet, sshKey, hw, "hash-"+uuid); err != nil {
+	if _, _, err := st.RegisterAppliance(uuid, macSet, sshKey, hw, "hash-"+uuid, "ABCDEF"); err != nil {
 		t.Fatalf("register appliance: %v", err)
 	}
 	list, err := st.ListUnclaimedAppliances()