ui: explicit Save button for shadow book settings

The shadow book toggle saved on change and the numeric fields on blur,
inconsistent with every other admin panel (which stages edits behind a
Save button). Stage all four fields in local state and commit them
together on Save, with an unsaved-changes hint. This also makes enabling
the live-trade toggle a deliberate two-step action rather than an
unguarded single click.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/components/admin/PerformanceSettings.tsx

@@ -49,6 +49,15 @@ export function PerformanceSettings() {
 
   if (window.isLoading || shadow.isLoading || !book) return <SkeletonCard />;
 
+  // Staged edits: nothing about the shadow book persists until Save, matching
+  // the other admin panels — and making the live-trade toggle deliberate.
+  const bookDirty =
+    !!shadow.data &&
+    (book.enabled !== shadow.data.enabled ||
+      book.capacity !== shadow.data.capacity ||
+      book.risk_pct !== shadow.data.risk_pct ||
+      book.start_equity !== shadow.data.start_equity);
+
   return (
     <div className="glass space-y-5 p-5">
       <div>
@@ -106,14 +115,15 @@ export function PerformanceSettings() {
           <input
             type="checkbox"
             checked={book.enabled}
-            onChange={(e) => saveBook.mutate({ enabled: e.target.checked })}
+            onChange={(e) => setBook({ ...book, enabled: e.target.checked })}
             className="mt-0.5"
           />
           <span>
             <span className="text-sm text-gray-200">Shadow book enabled</span>
             <span className="block text-[11px] leading-relaxed text-gray-500">
-              Starts opening real paper positions automatically on the next near-close scan. Verify its
-              first selections match a backtest of that day's cross-section before trusting the curve.
+              Starts opening real paper positions automatically on the next near-close scan — takes
+              effect when you Save. Verify its first selections match the top-ranked qualified setups
+              before trusting the curve.
             </span>
           </span>
         </label>
@@ -127,7 +137,6 @@ export function PerformanceSettings() {
               max={100}
               value={book.capacity}
               onChange={(e) => setBook({ ...book, capacity: Number(e.target.value) })}
-              onBlur={() => saveBook.mutate({ capacity: book.capacity })}
               className="input-glass w-full px-3 py-2 text-sm"
             />
           </label>
@@ -140,7 +149,6 @@ export function PerformanceSettings() {
               max={10}
               value={book.risk_pct}
               onChange={(e) => setBook({ ...book, risk_pct: Number(e.target.value) })}
-              onBlur={() => saveBook.mutate({ risk_pct: book.risk_pct })}
               className="input-glass w-full px-3 py-2 text-sm"
             />
           </label>
@@ -152,7 +160,6 @@ export function PerformanceSettings() {
               step={1000}
               value={book.start_equity}
               onChange={(e) => setBook({ ...book, start_equity: Number(e.target.value) })}
-              onBlur={() => saveBook.mutate({ start_equity: book.start_equity })}
               className="input-glass w-full px-3 py-2 text-sm"
             />
           </label>
@@ -161,6 +168,20 @@ export function PerformanceSettings() {
           Defaults match the validated configuration: 10 positions, 1% fixed-fractional risk. Start
           equity is only a sizing base — the books are compared in R-multiples, not currency.
         </p>
+
+        <div className="mt-4 flex items-center gap-3">
+          <button
+            type="button"
+            className="btn-primary px-4 py-2 text-sm disabled:opacity-50"
+            disabled={!bookDirty || saveBook.isPending}
+            onClick={() => saveBook.mutate(book)}
+          >
+            {saveBook.isPending ? 'Saving…' : 'Save shadow book'}
+          </button>
+          {bookDirty && !saveBook.isPending && (
+            <span className="text-[11px] text-amber-400/80">Unsaved changes</span>
+          )}
+        </div>
       </div>
     </div>
   );