Safer Saving

[jthrilly]

We have had reports from users of corrupted files while working in Architect, and so would like to change the way that saving works to help with this.

Proposed plan:

• Opening will continue to work on an unbundled temporary protocol in a temp directory, but will also immediately create a duplicate of the protocol that was opened in the same location as the protocol, in the format {protocol-name}.netcanvas.backup-{timestamp}. Failure to create the backup file will be a hard failure for the open process.
• Editing works as usual
• When saving:
  • the app zips the protocol inside the temp directory
  • once complete it tries to open the zip contents to verify it is a valid zip (there may be a better way to validate a zip using a library)
  • if this succeedes, the temp bundled protocol is copied to the user location.
  • if the copy succeedes, the temporary file is deleted, and a new temporary file is created.
• When closing an open protocol without saving, the temporary file is deleted (including when closing the app)
• Errors in the process should alert the user to the backup file and tell them how to restore (by renaming it)