fix(ux): resolve tickets #55 #56 — resource modal stability and success feedback

#55: Add SuccessToast after new resource is created. ResourceModal gains an
optional onSuccess(displayName) prop; ResourcesClient wires it to a toast
that auto-dismisses after 2.5 s.

#56: Fix useFocusTrap stale-closure bug. Focusable elements are now queried
dynamically inside handleKeyDown (not captured once at mount), so Tab
navigation stays correct as the form re-renders. Initial focus is deferred
via requestAnimationFrame so the browser layout is stable before focus() fires.

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/resources/ResourceModal.tsx

@@ -161,6 +161,7 @@ interface ResourceModalProps {
   mode: "create" | "edit";
   resource?: Resource;
   onClose: () => void;
+  onSuccess?: (displayName: string) => void;
 }
 
 const INPUT_CLASS =
@@ -189,7 +190,7 @@ function Spinner() {
   );
 }
 
-export function ResourceModal({ mode, resource, onClose }: ResourceModalProps) {
+export function ResourceModal({ mode, resource, onClose, onSuccess }: ResourceModalProps) {
   const [form, setForm] = useState<FormState>(() =>
     resource ? resourceToFormState(resource) : defaultFormState(),
   );
@@ -324,7 +325,12 @@ export function ResourceModal({ mode, resource, onClose }: ResourceModalProps) {
 
     try {
       if (mode === "create") {
-        await createMutation.mutateAsync(payload);
+        const created = await createMutation.mutateAsync(payload);
+        void utils.resource.directory.invalidate();
+        void utils.resource.listStaff.invalidate();
+        onSuccess?.(created.displayName);
+        onClose();
+        return;
       } else if (resource) {
         await updateMutation.mutateAsync({ id: resource.id, data: payload });
       }