fix(clients): later image reads show updated file contents#23510

fix(scripts): seed Read fixture paths with JSON escaping

Merge main into fix/issue-13138

test: retain only captured web evidence fixtures

test: add native static Read image fixture

test(client-runtime): each Read key signs its own asset URL

test: add reproducible Read image cache fixture

fix(client-runtime): a later image Read shows the file as it is now

test(client-runtime): a later image Read gets its own signed URL