docs: scope C15's freshness claim to the answering node, and file C33

[vieiralucas]

Doc-only follow-up to C15 (#368), from its final review pass.

• ARCHITECTURE §Named Versions: "current policy governs a version read" was silent on whose current. The doc-ACL tuples ride the room's log, so a follower that has not yet replicated a revoke redacts by the grants it still holds. Scoped the claim to the node answering.
• C33 filed: VersionFetch has no read-routing gate at all — Subscribe runs read_redirect_response (a follower serves only when caught up to the client's floor) and the version mutations redirect to the leader outright, but a fetch answers from local state unconditionally. Not a regression, and the live fan-out on the same follower is equally stale; the version seam is where the staleness is unbounded by the client, since a fetch names no sequence and so cannot be refused for being behind one. Distinct from C29, where the gate fails open for want of a creator rather than working on stale inputs.

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Summary by cubic

Clarifies that version reads use the policy current on the node answering, not the version’s captured ACLs, so a lagging follower may redact using stale grants. Files C33 to track that VersionFetch lacks a read-routing gate and should route like Subscribe to avoid stale reads.

^{Written for commit cd4c327. Summary will update on new commits.}