Repair shared claim and managed worker grants for #8

[grove]

Summary

This is the standalone core-maintenance prerequisite for issue #8. It fixes shared claim ambiguity and lets the configured MDM worker deliver a real future-deadline callback while business tables are idle. It does not complete issue #8's full temporal-escalation outcome or claim S1 release readiness.

• Appends core SQL 0.46.1 install and adjacent 0.46.0-to-0.46.1 upgrade artifacts while preserving historical SQL.
• Adds only the approved managed_cycle EXECUTE and generated-stream MAINTAIN grant lifecycle, with temporary SET LOCAL ROLE around managed_cycle, login identity preserved, and cleanup on success/failure.
• Adds PostgreSQL 18 coverage for complete claim results/errors, an idle future-deadline callback, role reset/rotation, denied callers, and populated upgrade behavior.

Delivery route: standalone maintenance contract v4 (sha256:7374c1202ba2c0b66901cf71882490e8bdf0ee3038f5dafbe22c513004e6a25a; Parent: None), destination main, head codex/issue-8-core-claim-maintenance. This is prerequisite work for issue #8; it does not close that issue.

Evidence

• REVIEWED report: .p2p/work/issue-8-core-claim-maintenance/review.md (sha256:2da90f63a21d7906768dc089fc59f6c1404c4416ad08556ee2195a02e908f011); no material findings.
• PROVEN report: .p2p/work/issue-8-core-claim-maintenance/proof.md (sha256:5ced357138c35c56524167fa17dfacb93c40a6dd13f23669835f357bd9639a79); all five maintenance requirements proven.
• The PostgreSQL 18.4 combined-image audit passed 19/19 named lanes; static package checks, fresh install, and populated upgrade passed. Rust format, check, and Clippy passed.
• Standalone host unit tests cannot link PostgreSQL backend symbols on macOS; the release build and runtime/upgrade behavior ran in the retained PostgreSQL 18 image. Full report files are local P2P records and are excluded from the commit.

The separate S1 decision remains INPUT_BLOCKED pending workload/churn measurements, owner-confirmed complete escalation fixtures, a signed numeric operating envelope, and an approved released pg_trickle build. This PR does not claim S1 GO.

Review comparison

• Candidate C: snapshot:sha256:27adf692841308ae79f54f5336b76dc39a8270e94ed31a28f693a41f42db2ac4.
• Frozen review comparison base A: c9c2077.
• Observed destination tip D on main: c9c2077 (unchanged from A).
• Proposed publication commit: one commit from parent A with message "Fix shared core claim and managed worker grants for issue v0.49.0: Deliver managed deadlines and bounded escalation #8"; its full SHA will be recorded with the snapshot-to-commit mapping.

The saved review and proof establish acceptance for C against A only; they do not establish compatibility with commits after A.

Merge readiness: NOT ASSESSED.

Merge Danger

Door: Two-way

Blast Radius: Core claim, the 0.46.1 extension upgrade path, and managed-worker privileges.