Release v2.0.0: vault security overhaul & GitLab sync fixes - Rename repo digital-will-hidden -> lastnote-vault - Replace SHA-256 key derivation with Argon2id - Native Go recursive copy for cross-platform image sync - Clone-once-then-pull git sync strategy - Fix images not syncing on release creation - Fix GitLab sync firing on every save - Improved error handling and modal settings UX