data-mesher: don't set owner for public_key

Doesn't seem to be a pattern yet with a single check.

checks/flake-module.nix

@@ -14,7 +14,7 @@ in
     ./installation/flake-module.nix
     ./morph/flake-module.nix
     ./nixos-documentation/flake-module.nix
-    ./sanity-checks/dont-depend-on-repo-root.nix
+    ./dont-depend-on-repo-root.nix
   ];
   perSystem =
     {

clanModules/data-mesher/shared.nix

@@ -105,10 +105,7 @@ in
           private_key = {
             inherit owner;
           };
-          public_key = {
-            inherit owner;
-            secret = false;
-          };
+          public_key.secret = false;
         };
 
       runtimeInputs = [
@@ -134,10 +131,7 @@ in
           private_key = {
             inherit owner;
           };
-          public_key = {
-            inherit owner;
-            secret = false;
-          };
+          public_key.secret = false;
         };
 
       runtimeInputs = [

nixosModules/clanCore/vars/default.nix

@@ -58,7 +58,25 @@ in
               )
             )
             ''
-              The config.clan.core.vars.generators.${generator.name}.files.${file.name} is not secret, but has non-default owner/group/mode set.
+              The config.clan.core.vars.generators.${generator.name}.files.${file.name} is not secret:
+              ${lib.optionalString
+                (file.owner != "root")
+                ''
+                  The owner is set to ${file.owner}, but should be root.
+                ''
+              }
+              ${lib.optionalString
+                (file.group != (if _class == "darwin" then "wheel" else "root"))
+                ''
+                  The group is set to ${file.group}, but should be ${if _class == "darwin" then "wheel" else "root"}.
+                ''
+              }
+              ${lib.optionalString
+                (file.mode != "0400")
+                ''
+                  The mode is set to ${file.mode}, but should be 0400.
+                ''
+              }
               This doesn't work because the file will be added to the nix store
             ''
       ) [ ] (lib.attrValues generator.files)