232c03ed1b
- HistoryUpdate Primary gate now reads IHistoryUpdateRoleView (PrimaryGatePolicy.ShouldServeHistoryUpdate): the data-plane verdict but CLOSED until this node's first redundancy snapshot, so both pair nodes cannot accept in the pre-join boot window. Single nodes open on their own singleton's first snapshot; admin-only nodes register no view => no gate. DriverHostActor publishes it at every Primary-verdict publish point. - SqlServer v1: the updater throws NotSupportedException on every arm; the node manager maps it to a node-level BadHistoryOperationUnsupported (was per-item under a Good node for UpdateData/DeleteAtTime). HistoryWrite bit still advertised on v1 (not knowable at materialise time) — documented. - The update plan is evaluated before the Primary gate: an unservable request (Remove, IsDeleteModified, not historized, no updater) is BadHistoryOperationUnsupported off-Primary, not BadInvalidState. - Local-kind SourceTimestamp converted to UTC before the future-skew compare and sent as UTC. - Hosted-service wiring extracted to BuildHistoryUpdatePosture and tested (gate source, skew, clock). - Docs: Historian.md (boot window, ordering, node-level v1, HistoryWrite bit), CLAUDE.md. Co-Authored-By: Claude <noreply@anthropic.com>