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/ajv/dist/refs/json-schema-2020-12/index.d.ts

@@ -0,0 +1,2 @@
+import type Ajv from "../../core";
+export default function addMetaSchema2020(this: Ajv, $data?: boolean): Ajv;