fix(frontend): English UI strings for session menu/dialogs; rename empty-guard + cancel test

- SessionMenu: anglicize all Italian labels (Vista divisa → Split view, etc.)
- RenameDialog: add empty-name guard + change title to "Rename session"
- DeleteConfirmDialog: translate title and description to English
- SessionActions.test: add 2 new tests (empty name guard, cancel on DeleteConfirmDialog)

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

frontend/src/shell/DeleteConfirmDialog.tsx

@@ -12,9 +12,9 @@ export function DeleteConfirmDialog({ open, label, onOpenChange, onConfirm }: Pr
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
       <DialogContent>
-        <DialogHeader><DialogTitle>Elimina definitivamente</DialogTitle></DialogHeader>
+        <DialogHeader><DialogTitle>Delete permanently</DialogTitle></DialogHeader>
         <DialogDescription>
-          "{label}" verrà eliminata definitivamente, inclusi tutti i suoi documenti. L'operazione non è reversibile.
+          "{label}" will be permanently deleted, including all of its documents. This action cannot be undone.
         </DialogDescription>
         <DialogFooter>
           <Button type="button" variant="outline" size="sm" onClick={() => onOpenChange(false)}>Cancel</Button>

frontend/src/shell/RenameDialog.tsx

@@ -15,6 +15,7 @@ export function RenameDialog({ open, initial, onOpenChange, onSubmit }: Props) {
 
   function submit(e: React.FormEvent) {
     e.preventDefault();
+    if (!name.trim()) return;
     onSubmit(name.trim());
     onOpenChange(false);
   }
@@ -22,7 +23,7 @@ export function RenameDialog({ open, initial, onOpenChange, onSubmit }: Props) {
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
       <DialogContent>
-        <DialogHeader><DialogTitle>Rinomina sessione</DialogTitle></DialogHeader>
+        <DialogHeader><DialogTitle>Rename session</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>

frontend/src/shell/SessionActions.test.tsx

@@ -7,7 +7,7 @@ import { DeleteConfirmDialog } from "./DeleteConfirmDialog";
 test("RenameDialog submits the edited name", async () => {
   const onSubmit = vi.fn();
   render(<RenameDialog open initial="Vecchio" onOpenChange={vi.fn()} onSubmit={onSubmit} />);
-  const input = screen.getByLabelText(/name/i);
+  const input = screen.getByDisplayValue("Vecchio");
   await userEvent.clear(input);
   await userEvent.type(input, "Nuovo");
   await userEvent.click(screen.getByRole("button", { name: /save/i }));
@@ -21,3 +21,19 @@ test("DeleteConfirmDialog confirms only on the destructive button", async () =>
   await userEvent.click(screen.getByRole("button", { name: /delete/i }));
   expect(onConfirm).toHaveBeenCalled();
 });
+
+test("RenameDialog does not submit an empty name", async () => {
+  const onSubmit = vi.fn();
+  render(<RenameDialog open initial="Old" onOpenChange={vi.fn()} onSubmit={onSubmit} />);
+  const input = screen.getByDisplayValue("Old");
+  await userEvent.clear(input);
+  await userEvent.click(screen.getByRole("button", { name: /save/i }));
+  expect(onSubmit).not.toHaveBeenCalled();
+});
+
+test("DeleteConfirmDialog does not confirm when Cancel is clicked", async () => {
+  const onConfirm = vi.fn();
+  render(<DeleteConfirmDialog open label="X" onOpenChange={vi.fn()} onConfirm={onConfirm} />);
+  await userEvent.click(screen.getByRole("button", { name: /cancel/i }));
+  expect(onConfirm).not.toHaveBeenCalled();
+});

frontend/src/shell/SessionMenu.tsx

@@ -29,10 +29,10 @@ export function SessionMenu({ session, groups, onView, onRename, onMove, onNewGr
       <Menu.Portal>
         <Menu.Positioner side="bottom" align="end" sideOffset={4}>
           <Menu.Popup className="z-50 min-w-44 rounded-lg bg-popover p-1 text-popover-foreground shadow-md ring-1 ring-foreground/10 outline-none">
-            <Menu.Item className={itemCls} onClick={onView}>Vista divisa</Menu.Item>
-            <Menu.Item className={itemCls} onClick={onRename}>Rinomina</Menu.Item>
+            <Menu.Item className={itemCls} onClick={onView}>Split view</Menu.Item>
+            <Menu.Item className={itemCls} onClick={onRename}>Rename</Menu.Item>
             <Menu.SubmenuRoot>
-              <Menu.SubmenuTrigger className={itemCls}>Sposta nel gruppo ›</Menu.SubmenuTrigger>
+              <Menu.SubmenuTrigger className={itemCls}>Move to group ›</Menu.SubmenuTrigger>
               <Menu.Portal>
                 <Menu.Positioner side="right" align="start">
                   <Menu.Popup className="z-50 min-w-44 rounded-lg bg-popover p-1 text-popover-foreground shadow-md ring-1 ring-foreground/10 outline-none">
@@ -40,18 +40,18 @@ export function SessionMenu({ session, groups, onView, onRename, onMove, onNewGr
                       <Menu.Item key={g} className={itemCls} onClick={() => onMove(g)}>{g}</Menu.Item>
                     ))}
                     {session.group && (
-                      <Menu.Item className={itemCls} onClick={() => onMove("")}>Senza gruppo</Menu.Item>
+                      <Menu.Item className={itemCls} onClick={() => onMove("")}>No group</Menu.Item>
                     )}
-                    <Menu.Item className={itemCls} onClick={onNewGroup}>Nuovo gruppo…</Menu.Item>
+                    <Menu.Item className={itemCls} onClick={onNewGroup}>New group…</Menu.Item>
                   </Menu.Popup>
                 </Menu.Positioner>
               </Menu.Portal>
             </Menu.SubmenuRoot>
             <Menu.Item className={itemCls} onClick={onArchiveToggle}>
-              {session.archived ? "Ripristina" : "Archivia"}
+              {session.archived ? "Restore" : "Archive"}
             </Menu.Item>
             <Menu.Separator className="my-1 h-px bg-border" />
-            <Menu.Item className={`${itemCls} text-destructive`} onClick={onDelete}>Elimina</Menu.Item>
+            <Menu.Item className={`${itemCls} text-destructive`} onClick={onDelete}>Delete</Menu.Item>
           </Menu.Popup>
         </Menu.Positioner>
       </Menu.Portal>