Returns the files attached to a branch from committed branch HEAD. Each reference is joined to its assets.primary descriptor when present, so the listed filename and size describe the immutable SHA-addressed blob. Older snapshots without asset metadata retain the legacy files-prefix lookup.

Read from the branch's saved snapshot rather than from the running project, so it works whether or not the project is open — and so a file attached since the last save is not listed yet.

A reference whose bytes are missing from storage is listed with a null size, because the object exists and omitting it would hide a half-finished upload. The reverse does not hold: stored bytes with no reference on this branch are not listed, since storage is shared across branches and one branch cannot tell an orphan from another branch's file.