After an OTA bundle is applied, show a one-time popup listing recent changes. The
changelog ships in the bundle (mobile/src/changelog.ts), so it is always in sync with
the code that just arrived. WhatsNewModal compares the newest entry id against the last
one seen (SecureStore); shows unseen entries, marks seen on dismiss, and stays quiet
until the next update adds an entry. First run shows only the newest entry (no history
dump). Mounted over the navigator when signed in.
Each OTA publish should prepend a new entry at the top of CHANGELOG.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
