On startup the server sync was kicked off 100ms after mount, racing
the first visible page's spreadsheet queries. Sync applies messages in
long synchronous stretches on the single worker thread, so account
balance calculations queued behind it (most noticeable on mobile).
Hold the initial sync until the accounts query has settled (with a 5s
fallback), so the first screen computes its balances before the sync
starts.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>