Every green native run killed the mid_git cell during git fetch (fetch was
in GIT_OPS and is the long step), so the merge-time index.lock schedule the
cell is named for never ran. A smudge filter the harness names in the
install's .git/config + .git/info/attributes (git's own filter hook; no
product change, no env var) now holds git merge while it writes
hermes_constants.py: index.lock held, the cell's new file and
hermes_cli/main.py already at the target, hermes_constants.py unlinked.
The kill point requires the hold, a merge/reset/checkout git child by argv
and index.lock; the cell asserts the lock was left. The fetch-time kill
keeps its own cell (mid_fetch).
(cherry picked from commit 592d57c3a9f78e04d617be659342e5338e080381)
(cherry picked from commit ba54f871bd580bb3fe9de7f840a7a21baf564dd2)
e60927ea89