feat: Implement PlayerActionManager for player actions and grid highlighting, SpecialTilesManager for special tile effects, and add freeze/hover tile meshes.

scripts/managers/player_action_manager.gd

@@ -76,7 +76,7 @@ func highlight_cells_if_authorized(cells_to_highlight: Array, item_id: int = -1)
 	
 	for cell in cells_to_highlight:
 		highlighted_cells.append(cell)
-		# Use Layer 2 for overlay highlights (prevents overwriting walls on Layer 0)
+		# Use Layer 2 for overlay highlights
 		enhanced_gridmap.set_cell_item(
 			Vector3i(cell.x, 2, cell.y),
 			highlight_item
@@ -181,8 +181,8 @@ func clear_highlights():
 			# Check Layer 2 (Overlay Highlight)
 			var l2_pos = Vector3i(cell.x, 2, cell.y)
 			var l2_item = enhanced_gridmap.get_cell_item(l2_pos)
-			# Only clear if it is a highlight and NOT a Safe Zone (ID 2)
-			if l2_item != -1 and l2_item != 2:
+			# Only clear if it is a highlight and NOT a Safe Zone (ID 2) or Freeze Area (ID 5)
+			if l2_item != -1 and l2_item != 2 and l2_item != 5:
 				enhanced_gridmap.set_cell_item(l2_pos, -1)
 	
 	highlighted_cells.clear()