image digest: include headings in image scan

Assumed that headings do not include images, obj_digest() looked
for images only in the non-heading branch, however, the markup
does not forbid one, and an object type left out of the scan
carries neither digest nor .ssp record, silently.

Open Issue: image_list, which drives pod bundling and the @doc_has
images count, is gathered only from para objects (and only the
first image of each), so an image in a heading or in a block body
is recorded in the abstraction but not bundled.

(assisted by Claude-Code)

0 files changed, 0 insertions, 0 deletions