Hushbox

Right-click any file or folder in Finder and choose Lock with Hushbox. It stays right where it is, locked. What is inside disappears from Spotlight, Recents and previews until you unlock it with Touch ID or your Hushbox password. Each locked item is an AES-256 encrypted disk image made with Apple's own tools, so it opens even without Hushbox. The original is deleted only after the locked copy is checked byte for byte. Hushbox locks itself when the screen locks, the Mac sleeps or after idle time, and asks before closing apps with unsaved work. No account, no cloud. Free for 24 hours, then $9 once; unlocking stays free. macOS 13 or later.