Optional(?) Strict Integrity Checks

[DavidBuchanan314]

SQLite doesn't even do checksumming by default. If data in our db got silently corrupted, we might end up emitting invalid diffs, etc. In these scenarios, it would be much better to panic.

Treating the db as an "untrusted" block store and checking the hash of everything we load could get expensive, but, it would essentially eliminate this.

It probably won't hurt perf significantly, and it'd be great for peace-of-mind.

I'll run some benchmarks before I decide whether it's optional/default/mandatory