RustBox 0.0.4

RustBox 0.0.4 improves attachment interaction in the message reader.

Highlights

Left-click previews supported attachment types in the in-app viewer.
Right-click exposes explicit Preview and Download actions.
Unsupported attachment types still download directly on left-click.
Attachments that exceed the preview limit now offer Download instead of only showing a warning.
Known oversized attachments are rejected before fetching their full payload for preview.