Enhance school creation and staffing management with native language support

- Updated protocol documentation to include `nativeLanguages` in `nameSets` and added `nativeLanguage` to school creation options.
- Enhanced the UI for school creation to allow selection of native languages, improving user experience.
- Revised API interfaces to accommodate new native language features, ensuring proper data handling.
- Improved localization strings to support new native language functionalities in both English and Russian.
- Updated tests to validate the new native language features and ensure robust functionality in staffing scenarios.

src/HSchool.People/RosterGenerator.cs

@@ -16,7 +16,8 @@ public static class RosterGenerator
         MapLayout map,
         int schoolSeed,
         string nameSetId,
-        DateTime? asOf = null)
+        DateTime? asOf = null,
+        string? nativeLanguage = null)
     {
         ArgumentNullException.ThrowIfNull(catalog);
         ArgumentNullException.ThrowIfNull(map);
@@ -27,6 +28,7 @@ public static class RosterGenerator
             throw new ArgumentException($"Unknown name set '{nameSetId}'.", nameof(nameSetId));
         }
 
+        var native = NativeLanguages.Pick(names, schoolSeed, nativeLanguage, rollIfOmitted: true);
         var when = DateTime.SpecifyKind(asOf ?? DefaultAsOf, DateTimeKind.Utc);
         var yearStart = SchoolYears.StartOn(when);
         var demand = SchoolDemand.From(catalog, map);
@@ -36,7 +38,7 @@ public static class RosterGenerator
         var families = new List<Family>(plans.Count);
         foreach (var plan in plans)
         {
-            var (family, members) = FamilyFactory.Create(catalog, names, schoolSeed, plan, yearStart, when);
+            var (family, members) = FamilyFactory.Create(catalog, names, schoolSeed, plan, yearStart, when, native);
             families.Add(family);
             people.AddRange(members);
         }