Sketches the pub.openletter.* record set — petition, draft, endorsement, objection, and contribution — and the reasoning behind it: account-owned data, CID-pinned signatures, immutable petition versions chained by supersedes, drafts as the mutable staging ground, and mutually-attested co-authorship. Also writes down the tradeoffs we're accepting and what we're leaving for later, so there's something concrete to react to. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>