ohmail for Android 0.1.0-beta.2

The second Android beta. Three changes, all from first-device feedback:

• First run opens with connecting. The app shows one welcome screen — what it is, then straight into pairing: scan the QR from your desktop's Devices screen or your self-hosted server's setup page, paste the pairing link, or type the address. A paired phone boots straight to mail.
• The demo dataset is gone. The app opens empty and shows only the mail of the server it is connected to. Features that are not built yet (compose, search, tags) are named as arriving later instead of being mocked.
• The launcher icon renders at the right size. The adaptive icon's mark now sits inside Android's safe circle instead of filling the whole mask.

The workflow attaches ohmail-android.apk (signed with the project's release key) to this release once the build completes. Installing over beta.1 keeps your pairings.