Default to fit-to-screen zoom on load when shapes exist

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: keyhell

src/components/replica-builder/lib/useBuilderState.ts

@@ -98,8 +98,13 @@ export function useBuilderState() {
     deleteHotkeysPlugin.attach(node);
     copyPastePlugin.attach(node);
     zoomPanPlugin.attach(node);
-    zoomPanPlugin.resetPan();
-    zoomPanPlugin.setZoom(1);
+    const initialBounds = shapeStore.allShapesBoundingBox;
+    if (initialBounds) {
+      zoomPanPlugin.fitToShapes(initialBounds);
+    } else {
+      zoomPanPlugin.resetPan();
+      zoomPanPlugin.setZoom(1);
+    }
 
     return () => {
       selectionPlugin.detach();