v0.2.5 – Ensure default barcode is served when none is found

- Implemented a fallback mechanism to serve `"0000000000000"` when no valid barcode is found in the clipboard.
- Ensured that the barcode is only updated when it actually changes, preventing redundant updates.
- Improved console logging by printing `"Barcode changed"` only when a new barcode is detected.
- Enhanced efficiency by reducing unnecessary writes to shared memory.

This update ensures that the barcode API (`http://localhost:3030/barcode`) always returns a valid 13-digit barcode, even when clipboard content doesn't contain one. 🚀

Author: mehmetakifkoz