The archive actions in the acting epic move whole skill/agent directories,
which the framework could not handle: snapshotFile used copyFile (EISDIR on
a directory) and the afterHash pass used readFile. Snapshots now branch on
lstat, copying directory trees with fs.cp recursive. Directories get an
empty afterHash ('' means no content hash) and drift detection skips the
hash comparison for them; the occupied-original-path check still applies and
a missing movedTo still falls back to the backup. Backup restore likewise
branches: a directory snapshot replaces the target (rm then cp recursive).
Apply-side rename cannot replace a directory destination (ENOTEMPTY), so a
move retries once after clearing the already-snapshotted destination,
rethrowing other codes before any destination damage.
Tests: archive a directory tree and restore it byte-identical, move a
directory onto an existing destination directory (destBackup taken, both
trees restored), and dir-move undo with an occupied original path refusing
without --force and overwriting with it.
Undo no longer clobbers files it did not create: an occupied original path
counts as drift for moves (--force removes then renames back), a move
destination that already exists is snapshotted (destBackup) and restored
after the file moves back, and a missing moved file falls back to the source
snapshot so forced undo cannot die mid-loop. Non-move reverts now key on
backup presence instead of the op label, which also restores files that a
create overwrote.
Apply snapshots once per unique path, hashes after all mutations so
overlapping changes carry the final state, and journals inside the rollback
region so a failed append reverts the mutations. The lock is taken with a
single wx write and goes stale by mtime only, so a fresh lock can never be
stolen while empty. Drift reads treat any unreadable target as drift with
its error code, ambiguous id prefixes report the match count, undo --last
skips already-undone records ("Nothing to undo."), and readRecords only
swallows ENOENT.
Tests cover each new behavior plus two mutation probes (forward-order revert
and removed locking both fail the suite), and a CLI-level check of
`act list --json` output shape and ordering.
Add src/act, a dependency-free framework for journaling and reverting any
file CodeBurn modifies. runAction is the single mutation path: it snapshots
every target, applies the changes, then appends a JSONL record, rolling back
completed steps and journaling nothing if a mutation throws midway. Undo
checks each file against its post-apply sha256 and refuses on drift unless
forced, restoring edits, deletes (created files), and moves. A pid plus
timestamp lockfile (stale after 60s) guards apply and undo, and the journal
reader tolerates corrupt lines with last-line-wins status updates.
Wire up `codeburn act list` (table or --json) and
`codeburn act undo <id|--last> [--force]`. Storage lives under the existing
config home via the config.ts resolver. Tests cover apply with backups and
afterHash, byte-identical undo per op type, drift refusal and --force,
mid-apply rollback, and corrupt-journal tolerance.
