73c17151f6 (Sep 29) persisted maintenance.auto=false, gc.auto=0 and
fetch.writeCommitGraph=false in treeless install checkouts. 6880ffc1af
stopped writing gc.auto=0 but never removed it, and `gc --auto` with
gc.auto=0 is a no-op (git skips every heuristic, gc.autoPackLimit included),
so the update's pack fold never ran on those checkouts: 203 -> 203 packs.
The previous commit's fingerprint required gc.writeCommitGraph=false, which
only the Oct 2 cut wrote, so the Sep 29 cohort also kept maintenance.auto=false.
Both cuts wrote maintenance.auto=false together with
fetch.writeCommitGraph=false and neither wrote
maintenance.commit-graph.enabled; that pair is now the fingerprint, and
gc.auto=0 is removed under it as well. An operator's own lone
maintenance.auto=false still never matches.
Real clear_git_debris() on a treeless clone with 203 lazy-fetch packs, git
2.53.0 and 2.55.0 alike:
Sep 29 keys: main 203 -> 203, #131741 203 -> 203, this 203 -> 1 (both keys gone)
Oct 2 keys: 203 -> 1, maintenance.auto gone
operator's own maintenance.auto=false: 203 -> 1, setting kept
a28aaa1edf