CUBED-mail 0.1.0-beta — Linux desktop build.

A sealed mail app: one inbox, one key, nothing else.

Per account you can switch on the sealed relay from the app's settings:
new mail for that mailbox then arrives with its body sealed to a key that
exists only inside this app (no server-side body search or recovery — the
point of the tier). Off by default. A 16-digit key opens the app. IMAP + SMTP across every
account you add, each with its own folder tree, newsletter filing, a local
danger scan, and the header's message count — the unread mail across every
account's INBOX. The store is sealed at rest; the 16-digit key you type on the
first run opens it, and changing the key later is done on the settings page.

Requires: a Linux desktop with GTK 3 and WebKitGTK 4.1 (Debian 13 trixie
ships both). Linux only.

Free to use. No source is included. Same licence as the CUBE-Contact Firefox
extension: it is free as well.

Install

    sh install.sh              (into ~/.local)
    PREFIX=/usr/local sudo sh install.sh

The installer puts the app and its mail engine (mailspike) under
$PREFIX/bin and adds a menu launcher. Start CUBED-mail from the menu, or run
the command the installer prints.

First run: the key page asks for 16 digits — type the key from your CUBED-mail
email, or any 16 digits you will keep. The key can be changed later under the
mail settings page (the gear).
