Ext/modules: expose module schemas

lib/frontmatter/default.nix

@@ -1,8 +1,20 @@
-{ lib }:
+{ lib, self }:
 let
   # Trim the .nix extension from a filename
   trimExtension = name: builtins.substring 0 (builtins.stringLength name - 4) name;
 
+  jsonWithoutHeader = self.lib.jsonschema {
+    includeDefaults = true;
+    header = { };
+  };
+
+  getModulesSchema =
+    modules:
+    lib.mapAttrs (
+      _moduleName: rolesOptions:
+      lib.mapAttrs (_roleName: options: jsonWithoutHeader.parseOptions options { }) rolesOptions
+    ) (self.lib.evalClanModulesWithRoles modules);
+
   evalFrontmatter =
     {
       moduleName,
@@ -90,7 +102,7 @@ in
 {
   inherit
     frontmatterOptions
-
+    getModulesSchema
     getFrontmatter
 
     checkConstraints