v0.9.8 — data-loss + duress-PIN hardening

v0.9.8 — data-loss + duress-PIN hardening

🐛 Fixes

• Encrypted-DB migration (#488): closes a rare window where a crash during the at-rest
  encryption migration could delete a valid encrypted chat database. The migration now confirms
  the file with a keyed open before ever treating it as a leftover.
• Duress PIN (#489): blocks setting a main PIN that collides with the duress PIN (which could
  silently wipe on the next unlock), resolves any pre-existing collision to unlock rather than
  wipe, and removes a visible "Preparing…" cue so a duress unlock looks like a normal one.

App-side only — the native library is unchanged. Seamless update; just refresh F-Droid.

Thanks to @x0net for both reports.