move trapdoor out of bootstrap

nt/primitives/bootstrap/default.nix

@@ -40,6 +40,5 @@ in
 
       maybe = ./maybe.nix;
       terminal = ./terminal.nix;
-      trapdoor = ./trapdoor.nix;
     }
   ]

nt/primitives/nt/default.nix

@@ -1,11 +1,11 @@
 {mix, ...} @ inputs:
 mix.newMixture inputs (mixture: {
-  includes = {
-    public = [
+  includes.public = [
     ./nt.nix
+    ./sig.nix
+    ./class.nix
   ];
-    protected = [
-      ./bootstrap
+  submods.public = [
+    ./trapdoor.nix
   ];
-  };
 })