fix(ui): use custom ConfirmDialog for deletions to prevent input blocking on Windows (#282)

src/components/layout/Sidebar.tsx

@@ -3,6 +3,7 @@
  * Navigation sidebar with menu items.
  * No longer fixed - sits inside the flex layout below the title bar.
  */
+import { useState } from 'react';
 import { NavLink, useLocation, useNavigate } from 'react-router-dom';
 import {
   Home,
@@ -22,6 +23,7 @@ import { useSettingsStore } from '@/stores/settings';
 import { useChatStore } from '@/stores/chat';
 import { Button } from '@/components/ui/button';
 import { Badge } from '@/components/ui/badge';
+import { ConfirmDialog } from '@/components/ui/confirm-dialog';
 import { useTranslation } from 'react-i18next';
 
 interface NavItemProps {
@@ -104,6 +106,7 @@ export function Sidebar() {
   };
 
   const { t } = useTranslation();
+  const [sessionToDelete, setSessionToDelete] = useState<{ key: string; label: string } | null>(null);
 
   const navItems = [
     { to: '/cron', icon: <Clock className="h-5 w-5" />, label: t('sidebar.cronTasks') },
@@ -170,12 +173,12 @@ export function Sidebar() {
                 {!s.key.endsWith(':main') && (
                   <button
                     aria-label="Delete session"
-                    onClick={async (e) => {
+                    onClick={(e) => {
                       e.stopPropagation();
-                      const label = getSessionLabel(s.key, s.displayName, s.label);
-                      if (!window.confirm(`Delete "${label}"?`)) return;
-                      await deleteSession(s.key);
-                      if (currentSessionKey === s.key) navigate('/');
+                      setSessionToDelete({
+                        key: s.key,
+                        label: getSessionLabel(s.key, s.displayName, s.label),
+                      });
                     }}
                     className={cn(
                       'absolute right-1 flex items-center justify-center rounded p-0.5 transition-opacity',
@@ -220,6 +223,22 @@ export function Sidebar() {
           )}
         </Button>
       </div>
+
+      <ConfirmDialog
+        open={!!sessionToDelete}
+        title={t('common.confirm', 'Confirm')}
+        message={sessionToDelete ? t('sidebar.deleteSessionConfirm', `Delete "${sessionToDelete.label}"?`) : ''}
+        confirmLabel={t('common.delete', 'Delete')}
+        cancelLabel={t('common.cancel', 'Cancel')}
+        variant="destructive"
+        onConfirm={async () => {
+          if (!sessionToDelete) return;
+          await deleteSession(sessionToDelete.key);
+          if (currentSessionKey === sessionToDelete.key) navigate('/');
+          setSessionToDelete(null);
+        }}
+        onCancel={() => setSessionToDelete(null)}
+      />
     </aside>
   );
 }

src/components/ui/confirm-dialog.tsx

@@ -0,0 +1,84 @@
+/**
+ * ConfirmDialog - In-DOM confirmation dialog (replaces window.confirm)
+ * Keeps focus within the renderer to avoid Windows focus loss after native dialogs.
+ */
+import { useEffect, useRef } from 'react';
+import { cn } from '@/lib/utils';
+import { Button } from '@/components/ui/button';
+
+interface ConfirmDialogProps {
+  open: boolean;
+  title: string;
+  message: string;
+  confirmLabel?: string;
+  cancelLabel?: string;
+  variant?: 'default' | 'destructive';
+  onConfirm: () => void;
+  onCancel: () => void;
+}
+
+export function ConfirmDialog({
+  open,
+  title,
+  message,
+  confirmLabel = 'OK',
+  cancelLabel = 'Cancel',
+  variant = 'default',
+  onConfirm,
+  onCancel,
+}: ConfirmDialogProps) {
+  const cancelRef = useRef<HTMLButtonElement>(null);
+
+  useEffect(() => {
+    if (open && cancelRef.current) {
+      cancelRef.current.focus();
+    }
+  }, [open]);
+
+  if (!open) return null;
+
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Escape') {
+      e.preventDefault();
+      onCancel();
+    }
+  };
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex items-center justify-center bg-black/50"
+      role="dialog"
+      aria-modal="true"
+      aria-labelledby="confirm-dialog-title"
+      onKeyDown={handleKeyDown}
+    >
+      <div
+        className={cn(
+          'mx-4 max-w-md rounded-lg border bg-card p-6 shadow-lg',
+          'focus:outline-none'
+        )}
+        tabIndex={-1}
+      >
+        <h2 id="confirm-dialog-title" className="text-lg font-semibold">
+          {title}
+        </h2>
+        <p className="mt-2 text-sm text-muted-foreground">{message}</p>
+        <div className="mt-6 flex justify-end gap-2">
+          <Button
+            ref={cancelRef}
+            variant="outline"
+            onClick={onCancel}
+          >
+            {cancelLabel}
+          </Button>
+          <Button
+            variant={variant === 'destructive' ? 'destructive' : 'default'}
+            onClick={onConfirm}
+          >
+            {confirmLabel}
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}