Spike: the art margin on unseen cards #52

Question. Does the 300-bit "confident" art threshold hold on cards the tuning never saw?

• Spec 011 kept 300 bits by ruling after one confident wrong match (284 against 299), to be revisited with an unseen-card sitting, perhaps with a gap rule.
• It matters before continuous scanning removes the tap that catches a wrong match.
• Needs a pile of cards the maintainer has at hand and hasn't scanned for tuning.
• No pass threshold; the maintainer rules on the findings.

A candidate from the roadmap. It is refined into a spec when its turn comes, and checked then against the north star's hosted-door rules and spec rules (one outcome, one PR; a spec that adds collector-owned data extends the export in the same PR).