fix(web): portal timeline overlays above stacked panels

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

@@ -2,6 +2,7 @@
 
 import { clsx } from "clsx";
 import { useEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
 import type { AllocationLike, AllocationReadModel, Assignment } from "@capakraken/shared";
 import { trpc } from "~/lib/trpc/client.js";
 import { useInvalidateTimeline } from "~/hooks/useInvalidatePlanningViews.js";
@@ -89,16 +90,17 @@ export function AllocationPopover({
   }
 
   if (isLoading || !allocation) {
-    return (
+    const loadingPopover = (
       <div ref={ref} style={style} className="bg-white border border-gray-200 rounded-xl shadow-xl p-4 text-sm text-gray-500">
         Loading...
       </div>
     );
+    return typeof document === "undefined" ? loadingPopover : createPortal(loadingPopover, document.body);
   }
 
   const dailyCostEUR = ((hoursPerDay ?? allocation.hoursPerDay) * (allocation.resource?.lcrCents ?? 0) / 100).toFixed(2);
 
-  return (
+  const popover = (
     <div
       ref={ref}
       style={style}
@@ -211,4 +213,6 @@ export function AllocationPopover({
       </div>
     </div>
   );
+
+  return typeof document === "undefined" ? popover : createPortal(popover, document.body);
 }