fix(frontend): horizontal-scroll table wrapper + portal Select dropdown

Make .table-wrapper overflow-x-auto so wide rows (long name + email)
stay reachable — the actions column (deactivate/reset password) was
clipped before. Render the Select option list in a body-level portal
with fixed positioning so it is never clipped by the scroll container.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/app/globals.css

@@ -110,7 +110,7 @@
 
   /* ─── Table ──────────────────────────────────────────── */
   .table-wrapper {
-    @apply overflow-hidden rounded-2xl border border-gray-200/80 bg-white shadow-sm;
+    @apply overflow-x-auto rounded-2xl border border-gray-200/80 bg-white shadow-sm;
   }
 
   /* ─── Loading skeleton ──────────────────────────────── */

frontend/src/components/ui/select.tsx

@@ -1,15 +1,17 @@
 'use client';
 
 import { useState, useRef, useEffect, useCallback } from 'react';
+import { createPortal } from 'react-dom';
 import { ChevronDown, Check } from 'lucide-react';
 
 export type SelectOption = { value: string; label: string; disabled?: boolean };
 
 /**
- * Lightweight custom dropdown. Unlike a native <select>, its option list is
- * absolutely anchored right below the trigger, so it can never render detached
- * at the top of the screen (a common mobile/emulator quirk). Flips above the
- * trigger automatically when there isn't enough room below.
+ * Lightweight custom dropdown. The option list is rendered into a body-level
+ * portal and anchored to the trigger with fixed positioning, so it is never
+ * clipped by an `overflow` ancestor (e.g. a horizontally-scrollable table
+ * wrapper). Flips above the trigger automatically when there isn't enough room
+ * below.
  */
 export function Select({
   value,
@@ -32,37 +34,68 @@ export function Select({
   disabled?: boolean;
 }) {
   const [open, setOpen] = useState(false);
-  const [flipUp, setFlipUp] = useState(false);
+  const [menuRect, setMenuRect] = useState<{
+    top: number;
+    left: number;
+    width: number;
+    flipUp: boolean;
+  } | null>(null);
   const rootRef = useRef<HTMLDivElement>(null);
+  const listRef = useRef<HTMLUListElement>(null);
   const selected = options.find((o) => o.value === value);
 
   const close = useCallback(() => setOpen(false), []);
 
+  const updatePosition = useCallback(() => {
+    if (!rootRef.current) return;
+    const rect = rootRef.current.getBoundingClientRect();
+    const spaceBelow = window.innerHeight - rect.bottom;
+    const flipUp = spaceBelow < 240 && rect.top > spaceBelow;
+    setMenuRect({
+      top: flipUp ? rect.top - 4 : rect.bottom + 4,
+      left: rect.left,
+      width: rect.width,
+      flipUp,
+    });
+  }, []);
+
   useEffect(() => {
     if (!open) return;
+    const isInside = (target: Node | null) =>
+      !!target &&
+      (rootRef.current?.contains(target) || listRef.current?.contains(target));
     const onDocClick = (e: MouseEvent) => {
-      if (rootRef.current && !rootRef.current.contains(e.target as Node)) close();
+      if (!isInside(e.target as Node)) close();
     };
     const onKey = (e: KeyboardEvent) => {
       if (e.key === 'Escape') close();
     };
+    // Fixed-positioned menu would detach from the trigger on scroll, so close it
+    // (unless the scroll happens inside the option list itself).
+    const onScroll = (e: Event) => {
+      if (!listRef.current?.contains(e.target as Node)) close();
+    };
     document.addEventListener('mousedown', onDocClick);
     document.addEventListener('keydown', onKey);
+    window.addEventListener('scroll', onScroll, true);
+    window.addEventListener('resize', close);
     return () => {
       document.removeEventListener('mousedown', onDocClick);
       document.removeEventListener('keydown', onKey);
+      window.removeEventListener('scroll', onScroll, true);
+      window.removeEventListener('resize', close);
     };
   }, [open, close]);
 
   const toggle = (e: React.MouseEvent) => {
     e.stopPropagation();
     if (disabled) return;
-    if (!open && rootRef.current) {
-      const rect = rootRef.current.getBoundingClientRect();
-      const spaceBelow = window.innerHeight - rect.bottom;
-      setFlipUp(spaceBelow < 240 && rect.top > spaceBelow);
+    if (open) {
+      setOpen(false);
+      return;
     }
-    setOpen((o) => !o);
+    updatePosition();
+    setOpen(true);
   };
 
   return (
@@ -86,12 +119,18 @@ export function Select({
         />
       </button>
 
-      {open && (
+      {open && menuRect && createPortal(
         <ul
+          ref={listRef}
           role="listbox"
-          className={`absolute z-50 left-0 right-0 max-h-60 overflow-auto rounded-xl border border-gray-200 bg-white py-1 shadow-lg ring-1 ring-black/5 ${
-            flipUp ? 'bottom-full mb-1' : 'top-full mt-1'
-          }`}
+          style={{
+            position: 'fixed',
+            top: menuRect.top,
+            left: menuRect.left,
+            width: menuRect.width,
+            transform: menuRect.flipUp ? 'translateY(-100%)' : undefined,
+          }}
+          className="z-[60] max-h-60 overflow-auto rounded-xl border border-gray-200 bg-white py-1 shadow-lg ring-1 ring-black/5"
         >
           {options.map((opt) => {
             const isSelected = opt.value === value;
@@ -120,7 +159,8 @@ export function Select({
               </li>
             );
           })}
-        </ul>
+        </ul>,
+        document.body,
       )}
     </div>
   );