Maps are editor-built scenes: [Tool] Playground/Crag, headless rebuild for agents

scenes/maps/playground.tscn and crag.tscn are generated by the map scripts' Rebuild (inspector
button, or godot-mono --headless --path . tools/rebuild_maps.tscn) and loaded as saved by the game,
so hand edits stick. The crag route is saved as Marker3D nodes and crag_spike checks the saved
scene. Layout verified identical to the code-built one (tools/map_dump.tscn).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/RebuildMaps.cs

@@ -0,0 +1,68 @@
+using Godot;
+
+// Headless map rebuild for agents (same as pressing each map's "Rebuild" button in the editor and
+// saving): loads each map scene, regenerates its children from code and saves it back.
+// godot-mono --headless --path . tools/rebuild_maps.tscn [-- only=playground|crag]
+// Prints "MAPS: rebuilt <path> (<n> nodes)" per map and "MAPS: done". Overwrites hand edits in those
+// scenes — that's what Rebuild means.
+public partial class RebuildMaps : Node
+{
+    public static readonly string[] Maps = { "res://scenes/maps/playground.tscn", "res://scenes/maps/crag.tscn" };
+
+    public override void _Ready()
+    {
+        string only = null;
+        foreach (string a in OS.GetCmdlineUserArgs())
+            if (a.StartsWith("only="))
+                only = a[5..];
+        bool ok = true;
+        foreach (string path in Maps)
+        {
+            if (only != null && !path.Contains(only))
+                continue;
+            ok &= RebuildOne(path);
+        }
+        GD.Print(ok ? "MAPS: done" : "MAPS: FAILED");
+        GetTree().Quit(ok ? 0 : 1);
+    }
+
+    private bool RebuildOne(string path)
+    {
+        Node map = ResourceLoader.Load<PackedScene>(path, null, ResourceLoader.CacheMode.Ignore).Instantiate();
+        AddChild(map);   // in the tree, so joint paths and globals resolve like in the editor
+        switch (map)
+        {
+            case Playground p:
+                p.Rebuild();
+                break;
+            case Crag c:
+                c.Rebuild();
+                break;
+            default:
+                GD.PushError($"MAPS: {path} root is not a map ({map.GetType().Name})");
+                return false;
+        }
+        RemoveChild(map);
+        PackedScene packed = new();
+        Error err = packed.Pack(map);
+        if (err == Error.Ok)
+            err = ResourceSaver.Save(packed, path);
+        int count = CountOwned(map, map);
+        map.Free();
+        if (err != Error.Ok)
+        {
+            GD.PushError($"MAPS: saving {path} failed: {err}");
+            return false;
+        }
+        GD.Print($"MAPS: rebuilt {path} ({count} nodes)");
+        return true;
+    }
+
+    private static int CountOwned(Node root, Node n)
+    {
+        int c = 0;
+        foreach (Node child in n.GetChildren())
+            c += (child.Owner == root ? 1 : 0) + CountOwned(root, child);
+        return c;
+    }
+}