iter_deleted_sqlite_sidecar_holders() and SessionDB._wal_generation_was_lost()
both treated a `` (deleted)`` suffix on a /proc/<pid>/fd/* target as proof that
state.db-wal or state.db-shm was unlinked. On OpenZFS that suffix is not proof:
a live, still-linked file whose dentry was unhashed is reported the same way,
with st_nlink still 1 and the same (dev, ino) as the path. The guard then fires
permanently and the gateway falls back to JSONL forever, because the WAL was
never actually deleted.
Add _fd_is_truly_unlinked(), which confirms via os.stat(fd_path).st_nlink == 0
before a target counts as an orphaned generation. An unstattable descriptor
still counts as deleted, so the guard keeps failing closed. _iter_proc_fd_targets()
and _proc_fd_targets() now also yield the /proc fd path itself so both call
sites (open-path and the sticky write-path probe) can run the check.
For each issue anchor present in BASE 63279301bc non-test .py and absent on HEAD, the BASE comment/docstring block was re-attached at the HEAD location of the code it explained (matched by the distinctive code line / enclosing def). Sentences already covered by an existing HEAD comment were deduped; the issue number always survives. Insert-only: no code lines changed.