Switch remote deploy to vendored source builds

Move remote deployment to a vendored source bundle built on the target host via Docker so redeploys no longer require local cross-compilation or host Go installation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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

@@ -0,0 +1,6 @@
+package dbus
+
+func (t *unixTransport) SendNullByte() error {
+	_, err := t.Write([]byte{0})
+	return err
+}