refactor(registry): add stable uid registry

registry/address.nix

@@ -1,4 +1,4 @@
-{ lib }:
+{ lib, ... }:
 {
   type = lib.types.str;
 }

registry/route.nix

@@ -1,4 +1,4 @@
-{ lib }:
+{ lib, ... }:
 {
   type = lib.types.submodule {
     options = {

registry/shell-shortcut.nix

@@ -1,4 +1,4 @@
-{ lib }:
+{ lib, ... }:
 let
   entryType = lib.types.submodule {
     options = {

registry/stable-uid.nix

@@ -0,0 +1,31 @@
+{ lib, ... }:
+let
+  inherit (lib)
+    filterAttrs
+    groupBy
+    mapAttrs
+    unique
+    ;
+
+  serviceNamesByUid = entries:
+    mapAttrs (_uid: uidEntries: unique (map (entry: entry.entry) uidEntries)) (
+      groupBy (entry: toString entry.value) entries
+    );
+
+  duplicateUids = entries:
+    filterAttrs (_uid: serviceNames: builtins.length serviceNames > 1) (serviceNamesByUid entries);
+
+in
+{
+  # Next stable UID: 20003
+  replicate = true;
+
+  type = lib.types.ints.positive;
+
+  validate = entries: [
+    {
+      assertion = duplicateUids entries == { };
+      message = "Stable UID allocations must be unique.";
+    }
+  ];
+}