fix: synchronize shadow book save state

frontend/src/components/admin/PerformanceSettings.tsx

@@ -41,6 +41,7 @@ export function PerformanceSettings() {
   const saveBook = useMutation({
     mutationFn: (payload: Partial<ShadowBookConfig>) => updateShadowBookSettings(payload),
     onSuccess: (data) => {
+      qc.setQueryData(['admin', 'shadow-book'], data);
       setBook(data);
       qc.invalidateQueries({ queryKey: ['admin', 'shadow-book'] });
       qc.invalidateQueries({ queryKey: ['paper-trades', 'performance'] });
@@ -115,8 +116,9 @@ export function PerformanceSettings() {
           <input
             type="checkbox"
             checked={book.enabled}
+            disabled={saveBook.isPending}
             onChange={(e) => setBook({ ...book, enabled: e.target.checked })}
-            className="mt-0.5"
+            className="mt-0.5 disabled:cursor-wait disabled:opacity-50"
           />
           <span>
             <span className="text-sm text-gray-200">Shadow book enabled</span>
@@ -136,8 +138,9 @@ export function PerformanceSettings() {
               min={1}
               max={100}
               value={book.capacity}
+              disabled={saveBook.isPending}
               onChange={(e) => setBook({ ...book, capacity: Number(e.target.value) })}
-              className="input-glass w-full px-3 py-2 text-sm"
+              className="input-glass w-full px-3 py-2 text-sm disabled:cursor-wait disabled:opacity-50"
             />
           </label>
           <label className="block space-y-1">
@@ -148,8 +151,9 @@ export function PerformanceSettings() {
               min={0.05}
               max={10}
               value={book.risk_pct}
+              disabled={saveBook.isPending}
               onChange={(e) => setBook({ ...book, risk_pct: Number(e.target.value) })}
-              className="input-glass w-full px-3 py-2 text-sm"
+              className="input-glass w-full px-3 py-2 text-sm disabled:cursor-wait disabled:opacity-50"
             />
           </label>
           <label className="block space-y-1">
@@ -159,8 +163,9 @@ export function PerformanceSettings() {
               min={1000}
               step={1000}
               value={book.start_equity}
+              disabled={saveBook.isPending}
               onChange={(e) => setBook({ ...book, start_equity: Number(e.target.value) })}
-              className="input-glass w-full px-3 py-2 text-sm"
+              className="input-glass w-full px-3 py-2 text-sm disabled:cursor-wait disabled:opacity-50"
             />
           </label>
         </div>