fix(frontend): configurable RenameDialog title; 'Rename group' for group rename

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/shell/AppShell.tsx

@@ -321,6 +321,7 @@ export function AppShell() {
           initial={renameGroupTarget}
           onOpenChange={(o) => { if (!o) setRenameGroupTarget(null); }}
           onSubmit={async (name) => { await renameGroup(renameGroupTarget, name); setRenameGroupTarget(null); }}
+          title="Rename group"
         />
       )}
       {deleteTarget && (

frontend/src/shell/RenameDialog.tsx

@@ -7,9 +7,10 @@ interface Props {
   initial: string;
   onOpenChange: (open: boolean) => void;
   onSubmit: (name: string) => void;
+  title?: string;
 }
 
-export function RenameDialog({ open, initial, onOpenChange, onSubmit }: Props) {
+export function RenameDialog({ open, initial, onOpenChange, onSubmit, title = "Rename session" }: Props) {
   const [name, setName] = useState(initial);
   useEffect(() => { if (open) setName(initial); }, [open, initial]);
 
@@ -23,7 +24,7 @@ export function RenameDialog({ open, initial, onOpenChange, onSubmit }: Props) {
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
       <DialogContent>
-        <DialogHeader><DialogTitle>Rename session</DialogTitle></DialogHeader>
+        <DialogHeader><DialogTitle>{title}</DialogTitle></DialogHeader>
         <form onSubmit={submit} className="flex flex-col gap-3">
           <div>
             <label className="mb-1.5 block text-xs font-medium text-muted-foreground" htmlFor="rename-name">Name</label>