Add Nix flake for mciasctl and mciasgrpcctl

Vendor dependencies and expose control program binaries via
nix build. Uses nixpkgs-unstable for Go 1.26 support.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vendor/github.com/go-webauthn/webauthn/metadata/status.go

@@ -0,0 +1,62 @@
+package metadata
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ValidateStatusReports checks a list of [StatusReport] structs against a list of desired and undesired [AuthenticatorStatus]
+// values. If the reports contain all of the desired and none of the undesired status reports then no error is returned
+// otherwise an error describing the issue is returned.
+func ValidateStatusReports(reports []StatusReport, desired, undesired []AuthenticatorStatus) (err error) {
+	if len(desired) == 0 && (len(undesired) == 0 || len(reports) == 0) {
+		return nil
+	}
+
+	var present, absent []string
+
+	if len(undesired) != 0 {
+		for _, report := range reports {
+			for _, status := range undesired {
+				if report.Status == status {
+					present = append(present, string(status))
+
+					continue
+				}
+			}
+		}
+	}
+
+	if len(desired) != 0 {
+	desired:
+		for _, status := range desired {
+			for _, report := range reports {
+				if report.Status == status {
+					continue desired
+				}
+			}
+
+			absent = append(absent, string(status))
+		}
+	}
+
+	switch {
+	case len(present) == 0 && len(absent) == 0:
+		return nil
+	case len(present) != 0 && len(absent) == 0:
+		return &Error{
+			Type:    "invalid_status",
+			Details: fmt.Sprintf("The following undesired status reports were present: %s", strings.Join(present, ", ")),
+		}
+	case len(present) == 0 && len(absent) != 0:
+		return &Error{
+			Type:    "invalid_status",
+			Details: fmt.Sprintf("The following desired status reports were absent: %s", strings.Join(absent, ", ")),
+		}
+	default:
+		return &Error{
+			Type:    "invalid_status",
+			Details: fmt.Sprintf("The following undesired status reports were present: %s; the following desired status reports were absent: %s", strings.Join(present, ", "), strings.Join(absent, ", ")),
+		}
+	}
+}