Sync breaks after a failed push

[wonder-sk]

If a push of a new version of the project fails for some reason (server error, network problem, ...), pending changes will be left in the working directory. However, the tool does a sanity check for any pending changes when woken up, and it will refuse to resume sync:

There are pending changes in the local directory - please review and push manually!

The tool keeps running, but does nothing - only sleeps and then complains about pending changes.

[Ojaybee]

Would it be useful to include a check for move or copy mode? If there are pending changes in the local directory in copy mode then we can just delete data in the working directory and pull from the Mergin server again until it is a clean mirror.

In _check_pending_changes() something like:

if (status_push["added"] or status_push["updated"] or status_push["removed"]) and config.operation_mode == "copy":
    logging.warning("Pending changes found: %s. Resetting local copy...", status_push)
    shutil.rmtree(config.project_working_dir)
    mc_download(mc)  # fresh download from Mergin server

This wouldn't work for move mode as it could lead to data loss.