v4.1.0

• Fixed Ctrl+Z/Ctrl+Y (Cmd+Z/Cmd+Shift+Z) doing nothing in the LaTeX formula textarea — React's controlled-input value tracking clears the browser's native undo stack on every keystroke (facebook/react#8873), so the textarea now has its own undo/redo stack
• Fixed Ctrl+Z/Ctrl+Y from any other focused control in the LaTeX dialog (checkboxes, buttons) leaking through to the canvas's own undo/redo behind the modal