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/debug/.eslintrc

@@ -0,0 +1,11 @@
+{
+  "env": {
+    "browser": true,
+    "node": true
+  },
+  "rules": {
+    "no-console": 0,
+    "no-empty": [1, { "allowEmptyCatch": true }]
+  },
+  "extends": "eslint:recommended"
+}