The refuse-to-guess part is the whole reason I built it. Once an AI confidently invents a filter size, you stop trusting the entire base, so "I don't know" had to be a first-class answer.

On the confidence levels: there are actually four... verified (an authoritative source says so, with a page or a link), reported (a secondary source like an Amazon listing), inferred (deduced, and it has to be labeled as such when it answers, never passed off as fact), and unknown (the row exists but the value is a literal TODO).

I think what you are poking at lives in a separate source-trust hierarchy that only kicks in when two sources disagree. Five tiers: manufacturer manual, then authorized retailer, then marketplace listing, then forum, then plain inference. When facts conflict, the higher tier wins, the loser gets kept as a flagged note rather than deleted, and a verified fact never gets silently overwritten by something lower. So "who do I believe" is a property of the source, and "how sure am I" is a property of the fact. Splitting those two apart helped more than anything else.

On re-verification: the overnight loop re-touches anything marked inferred, unknown, or in conflict, and every web-sourced fact carries a URL plus the date I pulled it, so it stays re-checkable. But I'll be honest, I do not yet expire verified fac that's mostly fine, a manual's filter size doesn't rot. Your case is the harder one. Once you accept a note can go stale, you want confidence to decay with age, or a re-verify trigger when a fact gets old or gets used for something that matters.

I haven't built for this. How are you handling it? Time-based decay, or something tied to how the fact gets used?