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.";
+    }
+  ];
 }