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/hono/dist/middleware/timing/index.js

@@ -0,0 +1,9 @@
+// src/middleware/timing/index.ts
+import { timing, setMetric, startTime, endTime, wrapTime } from "./timing.js";
+export {
+  endTime,
+  setMetric,
+  startTime,
+  timing,
+  wrapTime
+};