fix(web): portal timeline overlays above stacked panels

apps/web/src/components/timeline/NewAllocationPopover.tsx

@@ -2,6 +2,7 @@
 
 import { clsx } from "clsx";
 import { useEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
 import { AllocationStatus } from "@capakraken/shared";
 import { trpc } from "~/lib/trpc/client.js";
 import { useInvalidateTimeline } from "~/hooks/useInvalidatePlanningViews.js";
@@ -88,7 +89,7 @@ export function NewAllocationPopover({
 
   const canCreate = !!selectedProjectId && !!start && !!end && hoursPerDay > 0;
 
-  return (
+  const popover = (
     <div
       ref={ref}
       style={style}
@@ -238,4 +239,6 @@ export function NewAllocationPopover({
       </div>
     </div>
   );
+
+  return typeof document === "undefined" ? popover : createPortal(popover, document.body);
 }