Render a small JPEG preview for each stored document and show it at the
card's leading edge, falling back to the kind icon when none exists.
- Generate previews in the background on upload (new document-thumbnail
pg-boss queue) plus a boot-time corpus backfill for existing documents;
upload never blocks on or fails because of it. Images are downscaled via
@napi-rs/canvas, a PDF's first page is rasterised then downscaled, every
other type is skipped. Generation never throws.
- Store the preview encrypted at rest in a 1:1 DocumentThumbnail side table
(migration 0236) so the list/detail queries that omit the original blob
never drag the preview either. Same AES-256-GCM string codec + fail-closed
decrypt as the content index; wired into the key-rotation walk.
- Serve it through an owner-scoped GET /api/documents/inbound/[id]/thumbnail
(auth + module gate + userId-scoped query + fail-closed decrypt), always
image/jpeg + nosniff + private, no-store; 404 on miss. The card renders an
authed lazy <img>, onError falls back to the icon.
- Add hasThumbnail to the document DTO so the card only fetches a preview
that exists.
Also drop the "search looks inside your documents" caption from the overview
(the index-all prompt stays) and the per-card searchable marker; both were
noise. Remove the now-unused i18n keys across all six locales.
