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/node-server/dist/vercel.d.mts

@@ -0,0 +1,7 @@
+import * as http2 from 'http2';
+import * as http from 'http';
+import { Hono } from 'hono';
+
+declare const handle: (app: Hono<any, any, any>) => (incoming: http.IncomingMessage | http2.Http2ServerRequest, outgoing: http.ServerResponse | http2.Http2ServerResponse) => Promise<void>;
+
+export { handle };