An <img> can't send the X-Siftlode-Account header, so the poster.jpg request
resolved to the session-default account and _accessible_job 404'd it for any
download owned by a different (per-tab) account — every card then fell back to
the source's remote thumbnail, which for Facebook is an expiring fbcdn URL, so
the Library showed blank thumbnails in a multi-account session. The 0.69.1
local-poster-primary change made this the primary image, exposing it broadly.
Append ?account= to the poster URL via a new api.posterImageUrl(), the same
wallet-gated header-less selection downloadFileUrl / storyboardImageUrl already
use (resolved_user_id reads ?account= for exactly these contexts).
peter
ce2954cf2b