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/zod/src/v3/helpers/errorUtil.ts

@@ -0,0 +1,8 @@
+export namespace errorUtil {
+  export type ErrMessage = string | { message?: string | undefined };
+  export const errToObj = (message?: ErrMessage): { message?: string | undefined } =>
+    typeof message === "string" ? { message } : message || {};
+  // biome-ignore lint:
+  export const toString = (message?: ErrMessage): string | undefined =>
+    typeof message === "string" ? message : message?.message;
+}