feat: Implement enhanced card physics with rotational dynamics, mass scaling, stacking behavior, and drag torque.

frontend/src/desktop/LayoutSystem.ts

@@ -11,6 +11,7 @@ export interface LayoutCardState {
     rotation: number;
     width: number;
     height: number;
+    pageCount: number;
 }
 
 export class LayoutCard implements LayoutCardState {
@@ -21,6 +22,7 @@ export class LayoutCard implements LayoutCardState {
     rotation: number = 0;
     width: number = 0;
     height: number = 0;
+    pageCount: number = 1;
     ref: HTMLElement | null = null;
 
     private _innerRadius: number = 0;
@@ -50,8 +52,6 @@ export class LayoutCard implements LayoutCardState {
         this.applyTransform();
     }
 
-
-
     getConstrainedPosition(x: number, y: number): { x: number, y: number } {
         const rad = (this.rotation * Math.PI) / 180;
         const sin = Math.abs(Math.sin(rad));
@@ -90,6 +90,10 @@ export class LayoutCard implements LayoutCardState {
             this.recalculateCenters();
         }
 
+        if (changes.pageCount !== undefined) {
+            this.physics.updateMass(changes.pageCount);
+        }
+
         if (options.markDirty) {
             this.isDirty = true;
         }
@@ -240,7 +244,8 @@ export class LayoutCard implements LayoutCardState {
             z: this.z,
             rotation: this.rotation,
             width: this.width,
-            height: this.height
+            height: this.height,
+            pageCount: this.pageCount
         };
     }
 
@@ -278,6 +283,7 @@ export class LayoutStore {
     initialize(id: string, ref: HTMLElement | null, config: {
         width: number;
         height: number;
+        pageCount: number;
     }) {
         let card = this.items.get(id);
 
@@ -309,14 +315,16 @@ export class LayoutStore {
                     rotation,
                     width,
                     height,
-                    z
+                    z,
+                    pageCount: config.pageCount
                 }, ref);
             } else {
                 // Create card with temporary position
                 card = new LayoutCard(id, this, {
                     width,
                     height,
-                    z: this.zCounter++
+                    z: this.zCounter++,
+                    pageCount: config.pageCount
                 }, ref);
 
                 // Calculate initial position using the card instance
@@ -333,7 +341,7 @@ export class LayoutStore {
 
             this.items.set(id, card);
         } else {
-            card.update({ width, height }, { markDirty: false });
+            card.update({ width, height, pageCount: config.pageCount }, { markDirty: false });
         }
 
         // Always update ref and ensure transform is applied