validate cli command

[maraisr]

Following on from #2 be also kinda cool to have a command --validate or something to run in precommit to check if all derived and holistic images reconcile correctly. There should be zero I/O and simply exit 1 if there should be a change, as in creates a holistic image, or delete some files or whatever — and exit 0 if everything is as it should

[theKashey]

✅ verify command and API in v1.1.1