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>

AIClient/Assets/HotUpdate/Scripts/CharacterSpawner.cs

@@ -67,11 +67,11 @@ namespace HotUpdate
 
             _instance = Instantiate(prefab);
             _instance.name = "MaleExplorer_Runtime";
-            var y = _instance.transform.position.y;
-            _instance.transform.position = new Vector3(0f, y, 2.5f);
+            var plaza = GameObject.Find("TownSquare_Runtime");
+            var y = GroundSit.Height(Vector3.zero, plaza != null ? plaza.transform : null);
+            _instance.transform.position = new Vector3(0f, y, 0f);
             DontDestroyOnLoad(_instance);
 
-            // 仅对概念图 Billboard 子节点做朝向；真 3D 网格不要转，否则会拧成纸片
             var billboardTf = _instance.transform.Find("Billboard");
             if (billboardTf != null && Camera.main != null)
             {
@@ -82,8 +82,7 @@ namespace HotUpdate
                     billboardTf.rotation = Quaternion.LookRotation(-dir.normalized);
             }
 
-            // 调整主相机看向角色（竖屏）
-            if (Camera.main != null)
+            if (GameObject.Find("TownSquare_Runtime") == null && Camera.main != null)
             {
                 var cam = Camera.main;
                 cam.transform.position = new Vector3(0f, 1.2f, -2.2f);