Return all widths and heights in the resize done event.

tp-vsplitter.js

@@ -123,17 +123,28 @@ class TpVSplitter extends LitElement {
     document.body.style['userSelect'] = '';
     this.dragging = false;
 
-    let finalWidth;
+    let finalLeftWidth;
     if (this.lateResize && this._bufferedDelta) {
-      finalWidth = this._leftWidth + this._bufferedDelta;
+      finalLeftWidth = this._leftWidth + this._bufferedDelta;
       this.splitter.style.transform = '';
-      this.style.gridTemplateColumns = `${finalWidth}px 5px 1fr`;
+      this.style.gridTemplateColumns = `${finalLeftWidth}px 5px 1fr`;
       this._bufferedDelta = 0;
     } else {
-      finalWidth = this.left.offsetWidth;
+      finalLeftWidth = this.left.offsetWidth;
     }
 
-    this.dispatchEvent(new CustomEvent('resize-done', { detail: finalWidth, bubbles: true, composed: true }));
+    // Calculate right width
+    const splitterWidth = parseInt(getComputedStyle(this).getPropertyValue('--tp-splitter-width')) || 5;
+    const finalRightWidth = this.offsetWidth - finalLeftWidth - splitterWidth;
+
+    this.dispatchEvent(new CustomEvent('resize-done', { 
+      detail: { 
+        leftWidth: finalLeftWidth, 
+        rightWidth: finalRightWidth 
+      }, 
+      bubbles: true, 
+      composed: true 
+    }));
   }
 
   _resize(e) {