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.Simulation/School.cs

@@ -78,6 +78,9 @@ public sealed class School : IDisposable
     /// <summary>Name pack used to generate this school's people. Needed again on 1 September.</summary>
     public string? NameSetId { get; private set; }
 
+    /// <summary>Skill everyone generated for this school speaks natively.</summary>
+    public string? NativeLanguage { get; private set; }
+
     /// <summary>Last built table. Null until the worker installs people.</summary>
     public Timetable? Timetable { get; private set; }
 
@@ -115,7 +118,7 @@ public sealed class School : IDisposable
     /// <summary>
     /// Installs a roster that already matches the map. Spawns entities; does not write to disk.
     /// </summary>
-    public void InstallPeople(Roster roster, int seed, string? nameSetId = null, ApplicantPool? applicants = null)
+    public void InstallPeople(Roster roster, int seed, string? nameSetId = null, ApplicantPool? applicants = null, string? nativeLanguage = null)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);
         ArgumentNullException.ThrowIfNull(roster);
@@ -123,6 +126,7 @@ public sealed class School : IDisposable
         Roster = roster;
         PeopleSeed = seed;
         NameSetId = nameSetId;
+        NativeLanguage = nativeLanguage;
         Applicants = applicants;
         RosterSpawner.Spawn(World, roster);
         PlanDay = null;
@@ -282,7 +286,7 @@ public sealed class School : IDisposable
         var changed = false;
         foreach (var date in YearlyIntake.DatesBetween(before, after))
         {
-            Roster = YearlyIntake.Apply(Catalog, Roster, PeopleSeed, NameSetId, date);
+            Roster = YearlyIntake.Apply(Catalog, Roster, PeopleSeed, NameSetId, date, NativeLanguage);
             changed = true;
         }
 
@@ -304,7 +308,7 @@ public sealed class School : IDisposable
             return false;
         }
 
-        var next = Applicants.Advance(Catalog, Roster, PeopleSeed, NameSetId, Clock.Time);
+        var next = Applicants.Advance(Catalog, Roster, PeopleSeed, NameSetId, Clock.Time, NativeLanguage);
         if (next.Week == Applicants.Week)
         {
             return false;