Initial implementation of arca, a LUKS volume manager.

Go CLI using cobra with mount, unmount, status, and init subcommands.
Unlocks via udisks2 D-Bus (passphrase/keyfile) or cryptsetup (FIDO2/TPM2)
with ordered method fallback. Includes NixOS-specific LD_LIBRARY_PATH
injection for systemd cryptsetup token plugins.

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

vendor/github.com/godbus/dbus/v5/transport_generic.go

@@ -0,0 +1,52 @@
+package dbus
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"unsafe"
+)
+
+var nativeEndian binary.ByteOrder
+
+func detectEndianness() binary.ByteOrder {
+	var x uint32 = 0x01020304
+	if *(*byte)(unsafe.Pointer(&x)) == 0x01 {
+		return binary.BigEndian
+	}
+	return binary.LittleEndian
+}
+
+func init() {
+	nativeEndian = detectEndianness()
+}
+
+type genericTransport struct {
+	io.ReadWriteCloser
+}
+
+func (t genericTransport) SendNullByte() error {
+	_, err := t.Write([]byte{0})
+	return err
+}
+
+func (t genericTransport) SupportsUnixFDs() bool {
+	return false
+}
+
+func (t genericTransport) EnableUnixFDs() {}
+
+func (t genericTransport) ReadMessage() (*Message, error) {
+	return DecodeMessage(t)
+}
+
+func (t genericTransport) SendMessage(msg *Message) error {
+	fds, err := msg.CountFds()
+	if err != nil {
+		return err
+	}
+	if fds != 0 {
+		return errors.New("dbus: unix fd passing not enabled")
+	}
+	return msg.EncodeTo(t, nativeEndian)
+}