fix(searchable-select): reposition portal on scroll/resize

Adds scroll (capture) and resize listeners so the fixed-position dropdown
tracks its trigger as the page scrolls.

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

App/components/ui/searchable-select.tsx

@@ -34,13 +34,12 @@ export function SearchableSelect({
 
   useEffect(() => { setMounted(true); }, []);
 
-  // Recalculate portal position whenever the dropdown opens
+  // Recalculate portal position on open, scroll, and resize so the panel tracks
-  useLayoutEffect(() => {
+  // the trigger even when the page (or any ancestor) is scrolled.
-    if (!open || !containerRef.current) return;
+  const updatePortalPos = useCallback(() => {
+    if (!containerRef.current) return;
     const rect = containerRef.current.getBoundingClientRect();
     const PANEL_WIDTH = 420;
-    // Prefer right-aligning with the trigger; clamp so it doesn't go off-screen left
-    const right = window.innerWidth - rect.right;
     const left = Math.max(8, rect.right - PANEL_WIDTH);
     setPortalStyle({
       position: "fixed",
@@ -49,7 +48,23 @@ export function SearchableSelect({
       width: PANEL_WIDTH,
       zIndex: 9999,
     });
-  }, [open]);
+  }, []);
+
+  useLayoutEffect(() => {
+    if (!open) return;
+    updatePortalPos();
+  }, [open, updatePortalPos]);
+
+  useEffect(() => {
+    if (!open) return;
+    // capture:true catches scroll on any ancestor, not just window
+    window.addEventListener("scroll", updatePortalPos, true);
+    window.addEventListener("resize", updatePortalPos);
+    return () => {
+      window.removeEventListener("scroll", updatePortalPos, true);
+      window.removeEventListener("resize", updatePortalPos);
+    };
+  }, [open, updatePortalPos]);
 
   // Close on outside click / Escape
   useEffect(() => {