Adding big batch of structural code provided by Claude to start designing levels

Assets/_Project/Levels/PlayerZoneVolume.cs

@@ -0,0 +1,68 @@
+using UnityEngine;
+using TD.Core;
+
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+namespace TD.Levels
+{
+    /// <summary>
+    /// Authoring volume that defines a player's owned territory. Tiles covered by a
+    /// PlayerZoneVolume are <see cref="PlacementState.Buildable"/> in the baked grid (unless
+    /// covered by an Invalid-validity volume — Invalid wins).
+    /// </summary>
+    /// <remarks>
+    /// A single player's zone may consist of multiple PlayerZoneVolume instances with the same
+    /// <see cref="owner"/>; the bake unions their tile coverage. This supports L-shapes and other
+    /// non-rectangular zone footprints.
+    /// </remarks>
+    public class PlayerZoneVolume : VolumeBase
+    {
+        [Tooltip("Which player owns this zone.")]
+        public PlayerSlot owner = PlayerSlot.Player1;
+
+        [Tooltip("Whether tiles in this volume are buildable. Defaults to Allowed.")]
+        public PlacementValidity placementValidity = PlacementValidity.Allowed;
+
+        // Per-volume gizmo Y level (see gizmo design summary). Player zones draw lowest so
+        // overlapping spawners/leak exits/goals stack on top of them.
+        private const float FillYLevel = 0.02f;
+
+        protected override bool GetAlwaysShowToggle(LevelAuthoring authoring)
+        {
+            return authoring.alwaysShowPlayerZones;
+        }
+
+        // Selection-only by default. Always-on path runs from OnDrawGizmos when the toggle is set.
+        private void OnDrawGizmosSelected()
+        {
+            DrawGizmosCore();
+        }
+
+        private void OnDrawGizmos()
+        {
+            if (ShouldDrawAlwaysOn())
+            {
+                DrawGizmosCore();
+            }
+        }
+
+        private void DrawGizmosCore()
+        {
+            Color baseColor = PlayerColors.Get(owner);
+            DrawTileCoverageFill(baseColor, alpha: 0.35f, yLevel: FillYLevel);
+            DrawRectangularOutline(baseColor, yLevel: FillYLevel);
+
+#if UNITY_EDITOR
+            // Label centered on the volume's bounds, identifying which player owns this build area.
+            var col = Collider;
+            if (col != null)
+            {
+                Vector3 labelPos = new Vector3(col.bounds.center.x, FillYLevel + 0.1f, col.bounds.center.z);
+                Handles.Label(labelPos, $"{FormatPlayerName(owner)} Build Area");
+            }
+#endif
+        }
+    }
+}