Under `--json`, `snapshot list` prints no warning for a snapshot with
no manifest at the destination; the README now says so and points to
`remote_present`. The stdout list names `snapshot create` as well as
`snapshot restore` for the per-file error lines. `snapshot create`
stops "before it writes anything at the destination", since the
destination binding is saved first. `prune_grace_period` is a Go
duration, so the README now says only which units it rejects. The
commands that run while a backup is in progress are a bulleted list.
Model: fable-5-1
Warnings and the per-file errors of `snapshot restore` are written to stdout
through `internal/ui`, so the stdout list names them and the redirect example
says a file captures them. Only `make test` and `make lint` run inside Docker;
`make test-coverage` runs on the host. Some `Makefile` targets (`build`,
`clean`, `deps`, `test-coverage`, `local`, `install`) call no `script/` entry,
so "Most" replaces "only".
Fixes the two findings of the fourth review of
#399.
Model: fable-5-1
clawbot