Hide add-OP form for non-superadmin

PlayerManager no longer renders the "Add player" input + button when a
regular admin is viewing the Ops tab — the read-only banner remains so
they understand why.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

components/PlayerManager.tsx

@@ -162,7 +162,8 @@ export function PlayerManager() {
           ))}
         </div>
 
-        {/* Add player input */}
+        {/* Add player input — hidden on Ops tab for non-superadmin */}
+        {!(tab === "ops" && !isSuperadmin) && (
         <div className="flex flex-col sm:flex-row gap-2">
           <div className="flex-1">
             <Input
@@ -209,6 +210,7 @@ export function PlayerManager() {
             {tab === "ops" ? "Add OP" : tab === "whitelist" ? "Add" : "Ban"}
           </Button>
         </div>
+        )}
 
         <Separator />