Bote 3.0

• Hourly background sync and a "sync now" button with clear error messages • Invitation QR: always fits and scans on the first try • Optional end-to-end encryption of synced data • Attachments per event (photos and PDFs, local only) • Full backup to a single file • Configurable name (goodbye literal "Me") • Simpler closing: per-entry "paid" is gone • Detects your outgoing Bizum to mark you as settled • New icon (money bag) and assorted fixes