Enhance apparel definitions: Introduce 'UpperUnderwear' layer and related items (Bra, SportsBra, SoftBra) to support gender-specific clothing. Update inventory and dress generation logic to accommodate new layers and ensure proper coverage. Adjust localization for new apparel terms and refine tests for underwear functionality.

src/HSchool.Content/ApparelDefs.cs

@@ -7,6 +7,7 @@ namespace HSchool.Content;
 public static class ApparelLayers
 {
     public const string Underwear = "Underwear";
+    public const string UpperUnderwear = "UpperUnderwear";
     public const string Socks = "Socks";
     public const string Bottom = "Bottom";
     public const string Top = "Top";
@@ -17,10 +18,15 @@ public static class ApparelLayers
     public const string Accessory = "Accessory";
 
     public static readonly IReadOnlyList<string> All =
-        [Underwear, Socks, Bottom, Top, OverTop, Outer, Shoes, Head, Accessory];
+        [Underwear, UpperUnderwear, Socks, Bottom, Top, OverTop, Outer, Shoes, Head, Accessory];
 
     public static bool IsKnown(string layer) =>
         All.Any(candidate => candidate.Equals(layer, StringComparison.Ordinal));
+
+    public static bool IsUnder(string layer) =>
+        layer.Equals(Underwear, StringComparison.Ordinal)
+        || layer.Equals(UpperUnderwear, StringComparison.Ordinal)
+        || layer.Equals(Socks, StringComparison.Ordinal);
 }
 
 /// <summary>

src/HSchool.Content/Appropriateness.cs

@@ -213,7 +213,5 @@ public static class Appropriateness
     }
 
     private static bool IsUnderLayer(ThingDef def) =>
-        def.Layers.All(layer =>
-            layer.Equals(ApparelLayers.Underwear, StringComparison.Ordinal)
-            || layer.Equals(ApparelLayers.Socks, StringComparison.Ordinal));
+        def.Layers.All(ApparelLayers.IsUnder);
 }

src/HSchool.Content/CatalogLoader.cs

@@ -628,6 +628,14 @@ public sealed class CatalogLoader
             }
         }
 
+        foreach (var covered in thing.FullyCoversLayers)
+        {
+            if (!ApparelLayers.IsKnown(covered))
+            {
+                throw new ContentLoadException($"ThingDef '{thing.DefName}' fullyCoversLayers has unknown layer '{covered}'.");
+            }
+        }
+
         var colors = new HashSet<string>(StringComparer.Ordinal);
         foreach (var color in thing.Colors)
         {

src/HSchool.Content/Defs.cs

@@ -78,6 +78,12 @@ public sealed class ThingDef : Def
     /// <summary>Layers this occupies when worn. Empty — not apparel, so it can sit on the map.</summary>
     public IReadOnlyList<string> Layers { get; init; } = [];
 
+    /// <summary>
+    /// Worn layers fully hidden beneath this piece while condition stays above torn.
+    /// Example: pants list <see cref="ApparelLayers.Underwear"/>.
+    /// </summary>
+    public IReadOnlyList<string> FullyCoversLayers { get; init; } = [];
+
     /// <summary>Can live in a bag, locker or at home. Furniture stays false.</summary>
     public bool Portable { get; init; }