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/jose/dist/webapi/lib/private_symbols.js

@@ -0,0 +1 @@
+export const unprotected = Symbol();