hub v0.62.0 + scripts v1.19.0 — R-21 slice C: the universal secret-free ISO

A generic ISO carries NO customer secret. The box registers itself at the hub
as an unclaimed appliance; the operator binds it to a customer; the hub delivers
the customer-id + retrieval passphrase ONCE; day-0 completes via the slice-A path.

Hub (v0.62.0):
- store/appliance.go: appliance_registrations keyed by (uuid, mac_set) — MAC set
  is the tiebreaker (duplicate SMBIOS UUIDs); token stored as sha256 only.
  Idempotent register (sticky-discard), atomic one-shot delivery, bind/discard.
- api/appliance.go: POST /appliance/register (the one unauth endpoint, per-IP
  rate-limited, 256-bit token); GET /appliance/poll (404 no-oracle / 204 unbound
  / 200 deliver-once / 410 delivered). Passphrase read live, never logged.
- web/appliances.go: Hosts-page "Unclaimed appliances" section + BIND (customer
  picker, host count display-only) + DISCARD; SSH host-key fingerprints; events.
- Red-proofs: one-shot delivery + register idempotency (both proven red);
  404-no-oracle, sticky-discard, bind staging, render. Green + confirm gate.

Scripts (v1.19.0):
- felhom-bootstrap.sh: ONE unit, TWO modes. Direct (env has customer/passphrase)
  = slice-A path, byte-identical, only branched around. Pairing (generic) =
  register + poll (RestartSec=30 is the poll timer); on delivery write the env
  0600 and fall through to direct. Secrets + token shredded on success.
- build-felhom-iso.sh --pairing: generic secret-free ISO, -generic filename,
  manifest mode=pairing. profiles/generic.profile (new).
- test/bootstrap-modes.sh: Scenario D (direct = zero appliance calls) + pairing
  register/poll + delivery handoff — all green in a debian container.

hub/internal/web/hosts.go

@@ -334,8 +334,19 @@ func (s *Server) handleHostsList(w http.ResponseWriter, r *http.Request) {
 		rows = append(rows, row)
 	}
 
+	// R-21 slice C: the unclaimed-appliance section + bind picker.
+	unclaimed, picker, err := s.gatherUnclaimed(time.Now())
+	if err != nil {
+		s.logger.Printf("[ERROR] Hosts list: unclaimed appliances: %v", err)
+		// non-fatal: still render the host list
+	}
+
 	data := map[string]interface{}{
-		"Hosts": rows,
+		"Hosts":          rows,
+		"Unclaimed":      unclaimed,
+		"CustomerPicker": picker,
+		"Flash":          r.URL.Query().Get("flash"),
+		"CSRFToken":      s.getCSRFToken(r),
 	}
 	if err := s.templates.ExecuteTemplate(w, "hosts.html", data); err != nil {
 		s.logger.Printf("[ERROR] hosts.html template: %v", err)