A × closes a detail pane on a wide screen: Docker, Services, Cron

On a phone the list gives way to the pane and Back returns; on a desktop the list stays
beside it and there was no way to put the pane away.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

web/src/Services.tsx

@@ -137,6 +137,7 @@ function Detail({ name, onChanged, onBack }: { name: string; onChanged: () => vo
 
   return (
     <div className="svc-detail">
+      <button className="icon-btn detail-close" title="Close" aria-label="close" onClick={onBack}>×</button>
       <button className="btn back" onClick={onBack}>‹ Services</button>
       <div className="svc-head">
         <span className={'sdot ' + stateClass(d)} />