[ppXD]

Summary

• A new tool-call claim on a terminal agent run is refused with AgentRunEndedException. The run's status is read with its fence epoch under the same FOR SHARE and checked before the fence, so a run ended by completion, stop, abandon or recovery always answers "ended". An existing key still replays as Duplicate, and a run with no row keeps the epoch-0 rule. The park never parks a row whose run ended, and takes no run lock ahead of the row lock.
• StoppedRunDecisions.ExpireAsync closes Pending as well as AwaitingApproval decisions.
• The MCP handler answers a refused call with a final "run ended" result instead of "retry shortly", and a re-call of a still-Pending decision re-parks it, posting exactly one card.

Known gaps (follow-up)

• A write-approval row parked in the window after a stop's flip waits for the deadline reaper; only decision.request rows are closed by the stop's own close.
• ReplayOnEndedRunAsync returns InFlight for a Pending write row on an ended run, and ResumeOrTicketAsync then blocks until the lease reaper.
• Waking a call blocked on a closed decision and closing its card is left to a later backstop change.

Test plan

• Unit: full project (15157 passed, 1 skipped), including the run-ended text, Expired replay, Pending re-park posting one card, Pending to Expired edge
• Integration: StoppedRunDecisionFlowTests (47), ToolCallLedgerServiceTests (42), McpDecisionFlowTests (23)
• Integration over real UDS + Postgres: AgentMcpEndpointFlowTests (29 passed, 1 skipped), handler held at guard-to-claim and at claim-to-park
• Mutations (drop status check, refusal ahead of replay, drop Pending from ExpireAsync, restore retry text, fence checked before run end) each fail the suites