fix: Add debounced Undo/Redo system to avoid character-by-character history

- Add debounced state updates for title and content (500ms delay)
- Immediate UI updates with delayed history saving
- Prevent one-letter-per-undo issue
- Add cleanup for debounce timers on unmount

mcp-server/node_modules/math-intrinsics/isFinite.js

@@ -0,0 +1,12 @@
+'use strict';
+
+var $isNaN = require('./isNaN');
+
+/** @type {import('./isFinite')} */
+module.exports = function isFinite(x) {
+	return (typeof x === 'number' || typeof x === 'bigint')
+        && !$isNaN(x)
+        && x !== Infinity
+        && x !== -Infinity;
+};
+