Every cited block was read again at HEAD: no ref left to review, no
file name or hash literal added to a cited file since the pin
(--detect-new-files --watch-hashes), refs recaled with their pins.
Profiles built by a platform at a fixed commit, or whose bump would
leave prose under an older pin, stay where they were.
Profiles that read two repositories, a libretro port and its upstream,
now prefix each citation with source or upstream, decided by which tree
carries the cited value at its pin. The emulator pages use the word to
tell libretro glue, emulator code as the port carries it, and the
upstream emulator apart.