## Summary
Custom FILES field chips now show an inline image thumbnail for image
attachments and fall back to the legacy label when an attachment
predates filename storage. This covers two of the UX complaints n2ojim
collected in #20942: image files were indistinguishable from other
attachments, and older attachments rendered with an empty chip label.
The 10-file cap from the same issue already shipped in #20950; the
gallery/grid layout and hover-delete affordances are deliberately left
for follow-ups per the maintainer's cost notes on the thread.
## Why this matters
#20942 is founder-tagged UX feedback on the new custom FILES field: once
a record carries more than a couple of attachments, users scan chips
visually, and a thumbnail answers "which one is the screenshot" without
opening anything. The fallback keeps old records readable instead of
showing blank chips. Changes stay inside `FileChip.tsx` and follow the
existing file-display patterns; Storybook stories cover both behaviors.
## Testing
Added 9 Storybook stories: image attachment (thumbnail), non-image (icon
unchanged), missing filename (legacy fallback label), long names, and
combinations. Targeted typecheck of the changed files surfaced no
errors; the monorepo's CI lint/build covers the rest.
Refs #20942
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Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Etienne <45695613+etiennejouan@users.noreply.github.com>
Matt Van Horn
cb653e4ecc