feat(registry): validate unique addresses and routes

registry/address.nix

@@ -1,4 +1,11 @@
 { lib, ... }:
 {
   type = lib.types.str;
+
+  checks = [
+    {
+      assertion = lib.registry.predicates.uniqueValue (entry: entry.value);
+      message = "Address registry values must be unique.";
+    }
+  ];
 }

registry/route.nix

@@ -1,5 +1,12 @@
 { lib, ... }:
 {
+  checks = [
+    {
+      assertion = lib.registry.predicates.uniqueValue (entry: entry.value.domain);
+      message = "Route domains must be unique.";
+    }
+  ];
+
   type = lib.types.submodule {
     options = {
       domain = lib.mkOption {

registry/stable-uid.nix

@@ -22,9 +22,9 @@ in
 
   type = lib.types.ints.positive;
 
-  validate = entries: [
+  checks = [
     {
-      assertion = duplicateUids entries == { };
+      assertion = entries: duplicateUids entries == { };
       message = "Stable UID allocations must be unique.";
     }
   ];