Continued fixes to sync and stability. - Fixed an intermittent server crash when uploading letters (the root cause of some letters not being delivered in 1.0.0/1.0.1). - Fixed template names showing as raw localization keys (e.g. "template.future-self.title"). - Fixed a stuck "letter not uploaded" banner: a single bad letter no longer blocks the whole queue. - Fixed a privacy issue when switching accounts that could re-upload another user's letters. - Fixed concurrent network requests sometimes invalidating sign-in unnecessarily. - Fixed recurring check-in letters not firing notifications when dates fell into the past. If you saw a "not uploaded" banner, opening the app after updating should clear it automatically.

Fixes silent letter sync failures that prevented some scheduled letters from being delivered. What changed: - Added a sync retry queue: letters now retry uploading automatically when the network or session is restored, and the Home screen shows sync status. - Added a Diagnostics screen (Settings → Diagnostics) so you can copy a status report when contacting support. - Fixed an upgrade-time bug that could clear old data — your old library is now preserved automatically. - Fixed a wrong-version-number display on the About page. - Localized template text for English users. - Better handling when your sign-in expires — you're now guided back to sign-in instead of stuck silently. If you have letters that didn't arrive, open the app after updating — we'll automatically retry uploading every local letter.