Revert biome rework (#38724)

* Revert "Fix world generation (#38713)"

This reverts commit 10fa6ff4af.

* Revert "Biome rework (#37735)"

This reverts commit fe7b96147c.

Content.Shared/Procedural/PostGeneration/CorridorDecalSkirtingDunGen.cs

@@ -0,0 +1,31 @@
+namespace Content.Shared.Procedural.PostGeneration;
+
+/// <summary>
+/// Applies decal skirting to corridors.
+/// </summary>
+public sealed partial class CorridorDecalSkirtingDunGen : IDunGenLayer
+{
+    /// <summary>
+    /// Decal where 1 edge is found.
+    /// </summary>
+    [DataField]
+    public Dictionary<DirectionFlag, string> CardinalDecals = new();
+
+    /// <summary>
+    /// Decal where 1 corner edge is found.
+    /// </summary>
+    [DataField]
+    public Dictionary<Direction, string> PocketDecals = new();
+
+    /// <summary>
+    /// Decal where 2 or 3 edges are found.
+    /// </summary>
+    [DataField]
+    public Dictionary<DirectionFlag, string> CornerDecals = new();
+
+    /// <summary>
+    /// Optional color to apply to the decals.
+    /// </summary>
+    [DataField]
+    public Color? Color;
+}