A command killed part-way could leave a temporary file or directory of
secret.WriteFileAtomic or secret.TempDirFor, encrypted keys included,
for good. LockStateDir now empties the lock file once it holds the lock
and writes "finished" there just before releasing it. A holder that
does not find that deletes such leftovers from the state directory,
each vault, each secret and each version, the only places those helpers
make them, matching names that start with "." and hold ".tmp-". After a
command that finished nothing is searched, so the added time does not
grow with the number of secrets and versions. A test shows that
`unlocker remove` removes an unlocker directory with no metadata file.
Model: opus-5-5
Each command that changes the state directory holds one lock: flock(2)
on `lock` in the state directory, dropped by the kernel if the process
dies, or a process-wide mutex on the in-memory test filesystem. It
covers the state directory, not each vault, because `currentvault`,
`vault create` and cross-vault moves span vaults, and a lock file in a
vault would be deleted by `vault remove` under a waiting command.
Files go through `secret.WriteFileAtomic`; versions, new secrets and
cross-vault copies are built in a temporary directory and renamed into
place; removals rename out of the way first. Left for later: replacing
an unlocker (#71) and deleting
what an interrupted command leaves under a `.tmp-` name
(#75).
Model: opus-5-5
Co-authored-by: clawbot <sneak+clawbot@sneak.cloud>
clawbot