Add TownSquare scene assets, resource production docs, and model pipeline updates.

Bring in plaza props/prefabs, ZhaoYun source GLB, design originals, and Hunyuan/Blender tooling used to produce them.

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

Tools/model_tools/bl_restore_yup.py

@@ -0,0 +1,58 @@
+"""把游戏 FBX 整理成混元 GLB 轴向（Y-up）且原点在底面中点。可重复执行。
+调用：blender -b --factory-startup --python bl_restore_yup.py -- <fbx> [fbx...]
+"""
+import json
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+from bl_decimate import (  # noqa: E402
+    export_fbx_source_yup,
+    import_model_objects,
+    prepare_game_export,
+)
+
+
+def restore_file(path):
+    import bpy
+
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    imported = import_model_objects(path)
+    meshes = [o for o in imported if o.type == "MESH"]
+    if not meshes:
+        return {"path": path, "error": "no mesh"}
+    for obj in meshes:
+        prepare_game_export(obj)
+    bpy.ops.object.select_all(action="DESELECT")
+    for obj in meshes:
+        obj.select_set(True)
+    bpy.context.view_layer.objects.active = meshes[0]
+    export_fbx_source_yup(path)
+    verts = meshes[0].data.vertices
+    xs = [v.co.x for v in verts]
+    ys = [v.co.y for v in verts]
+    zs = [v.co.z for v in verts]
+    return {
+        "path": os.path.basename(path),
+        "meshes": len(meshes),
+        "min_y": round(min(ys), 6),
+        "mid_x": round((min(xs) + max(xs)) * 0.5, 6),
+        "mid_z": round((min(zs) + max(zs)) * 0.5, 6),
+    }
+
+
+def main():
+    argv = sys.argv[sys.argv.index("--") + 1 :]
+    results = []
+    for raw in argv:
+        path = os.path.abspath(raw)
+        if not os.path.isfile(path):
+            results.append({"path": raw, "error": "missing"})
+            continue
+        results.append(restore_file(path))
+    print("MT_SUMMARY " + json.dumps(results, ensure_ascii=False))
+
+
+if __name__ == "__main__" and "--" in sys.argv:
+    main()