Add more logging of timestamps in the actual code, and a few sanity
checks in unit tests.
These were useful while trying to find the root cause of #104218 and might
be useful in the future too. The solution to that issue will be committed
later.
`os.IsNotExist()` is from before `errors.Is()` existed. The latter is the
recommended approach, as it also recognised wrapped errors.
No functional changes, except for recognising more cases of "does not
exist" errors as such.
Shaman was made on Linux, using the `path` module, which only supports
forward slashes. This mostly replaces `path` with `path/filepath` to use
native paths and increase Windows compatibility.
The work isn't done yet, though.
This is a better way to check errors, both semantically (no usually nil is
bad, but nil error is good, so this avoids a mental negation) and for
the reporting by the assert package.
Flamenco v2 allowed separate configuration of the Shaman file store and
checkout paths. This is now just one setting for "the storage". The file
store will be in `{storage}/file-store` and the checkout will happen in
`{storage}/jobs`.
This is not yet working, it's just a direct copy of the Manager of Flamenco
2, with Logrus replaced by Zerolog. The API has been documented in
flamenco-manager.yaml as a starting point for the integration.
