Restore Slavic save lift and redress abstract underwear on load.

Recheck of slice 7 stage A found UpgradeOlderSave removed after UpperUnderwear, so format-2 nameSetId saves never started, and golden people.json wearing abstract Underwear failed RequireKnownApparel. Bring back the lift, treat unusable items as undressed, and restore GoldenSaveTests.

src/HSchool.People/DressGenerator.cs

@@ -71,7 +71,7 @@ public static class DressGenerator
         int? pupilYear,
         int age)
     {
-        if (person.Items.Count > 0)
+        if (person.Items.Count > 0 && ItemsUsable(catalog, person.Items))
         {
             return person;
         }
@@ -130,11 +130,12 @@ public static class DressGenerator
         return pool with { Applicants = applicants };
     }
 
-    public static bool NeedsDressing(Roster roster, ApplicantPool? pool)
+    public static bool NeedsDressing(DefCatalog catalog, Roster roster, ApplicantPool? pool)
     {
+        ArgumentNullException.ThrowIfNull(catalog);
         foreach (var person in roster.People)
         {
-            if (person.Items.Count == 0)
+            if (person.Items.Count == 0 || !ItemsUsable(catalog, person.Items))
             {
                 return true;
             }
@@ -147,7 +148,7 @@ public static class DressGenerator
 
         foreach (var applicant in pool.Applicants)
         {
-            if (applicant.Person.Items.Count == 0)
+            if (applicant.Person.Items.Count == 0 || !ItemsUsable(catalog, applicant.Person.Items))
             {
                 return true;
             }
@@ -156,6 +157,19 @@ public static class DressGenerator
         return false;
     }
 
+    private static bool ItemsUsable(DefCatalog catalog, IReadOnlyList<InventoryItem> items)
+    {
+        foreach (var item in items)
+        {
+            if (!catalog.Things.TryGetValue(item.Def, out var def) || def.Abstract)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /// <summary>
     /// Adds textbooks for subjects the pupil just became old enough for. Existing clothes stay.
     /// </summary>