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 +1,49 @@
+{ lib, ... }:
+let
+  inherit (lib)
+    concatStringsSep
+    foldl'
+    groupBy
+    unique
+    ;
+
+  duplicateUids = entries:
+    let
+      byUid = groupBy (entry: toString entry.value) entries;
+    in
+    foldl' (
+      acc: uid:
+      let
+        serviceNames = unique (map (entry: entry.entry) byUid.${uid});
+      in
+      if builtins.length serviceNames > 1 then
+        acc ++ [ {
+          uid = lib.toInt uid;
+          inherit serviceNames;
+        } ]
+      else
+        acc
+    ) [ ] (builtins.attrNames byUid);
+
+  renderUidConflict = conflict:
+    "${toString conflict.uid} is assigned to ${concatStringsSep ", " conflict.serviceNames}";
+in
+{
+  # Next stable UID: 20003
+  replicate = true;
+
+  type = lib.types.ints.positive;
+
+  validate = entries:
+    let
+      uidConflicts = duplicateUids entries;
+    in
+    [
+      {
+        assertion = uidConflicts == [ ];
+        message = ''
+          Duplicate stable UID allocation(s): ${concatStringsSep "\n" (map renderUidConflict uidConflicts)}
+        '';
+      }
+    ];
+}