feat(web): place full setup objects at their real transforms

Model TTSObjectTransform in shared types and convert each object's position, rotation, and scale into three.js placement, with per-class base-size corrections and a lay-flat rotation for extruded meshes.

packages/shared/src/types.ts

@@ -1,3 +1,20 @@
+/**
+ * An object's placement in the TTS world: position, rotation (degrees), and
+ * scale. TTS uses a left-handed system with Y up; `posZ` points toward the
+ * player. Present on every object in a save.
+ */
+export interface TTSObjectTransform {
+  posX: number;
+  posY: number;
+  posZ: number;
+  rotX: number;
+  rotY: number;
+  rotZ: number;
+  scaleX: number;
+  scaleY: number;
+  scaleZ: number;
+}
+
 /**
  * A single object inside a Tabletop Simulator save file.
  * Mirrors the structure produced by BSON-deserializing a TTS save.
@@ -11,6 +28,8 @@ export interface TTSObject {
   Description: string;
   /** Set by `markParent` during traversal; not present in the raw save. */
   Parent?: TTSObject;
+  /** Placement in the TTS world (position, rotation, scale). */
+  Transform?: TTSObjectTransform;
 
   CustomPDF?: {
     PDFUrl: string;