Let the catalog describe clothes and carryables on ThingDef without dressing anyone.

Empty layers keep furniture on the map; a known layer set and ColorDef palette reject unknown ids at load.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.Content/ApparelDefs.cs

@@ -0,0 +1,56 @@
+namespace HSchool.Content;
+
+/// <summary>
+/// Layers apparel occupies. Code, not a def — new layers are a rebuild, like
+/// <see cref="PersonRoles"/>.
+/// </summary>
+public static class ApparelLayers
+{
+    public const string Underwear = "Underwear";
+    public const string Socks = "Socks";
+    public const string Bottom = "Bottom";
+    public const string Top = "Top";
+    public const string OverTop = "OverTop";
+    public const string Outer = "Outer";
+    public const string Shoes = "Shoes";
+    public const string Head = "Head";
+    public const string Accessory = "Accessory";
+
+    public static readonly IReadOnlyList<string> All =
+        [Underwear, Socks, Bottom, Top, OverTop, Outer, Shoes, Head, Accessory];
+
+    public static bool IsKnown(string layer) =>
+        All.Any(candidate => candidate.Equals(layer, StringComparison.Ordinal));
+}
+
+/// <summary>
+/// ColorDef appropriateness tags. School rules filter these, not color names.
+/// </summary>
+public static class ColorTags
+{
+    public const string Neutral = "neutral";
+    public const string Bright = "bright";
+    public const string School = "school";
+
+    public static readonly IReadOnlyList<string> All = [Neutral, Bright, School];
+
+    public static bool IsKnown(string tag) =>
+        All.Any(candidate => candidate.Equals(tag, StringComparison.Ordinal));
+}
+
+/// <summary>Bottom length for the short-form dress code. Omit on things that have no hem.</summary>
+public static class SkirtLengths
+{
+    public const string Regular = "regular";
+    public const string Short = "short";
+
+    public static readonly IReadOnlyList<string> All = [Regular, Short];
+
+    public static bool IsKnown(string length) =>
+        All.Any(candidate => candidate.Equals(length, StringComparison.Ordinal));
+}
+
+public sealed class ColorDef : Def
+{
+    public IReadOnlyList<string> Tags { get; init; } = [];
+}