--- R5 before e34067edef2eba03c1e40bca7d2b2d933ae12b85
+++ R5 after dd3b029f5325ae8e67ca89f37c426bdbe92449e6
@@ -2,10 +2,9 @@
 {"ordinal": 1, "status": "running", "turn": "ROOT_TURN_1", "type": "provider_turn.updated"}
 {"lastError": null, "status": "running", "type": "provider_session.updated"}
 {"ordinal": 1, "status": "running", "turn": "ROOT_TURN_1", "type": "provider_turn.updated"}
-{"lastError": "Synthetic overflow O1", "status": "error", "type": "provider_session.updated"}
+{"label": "overflow-before-EOF", "session": {"lastError": null, "status": "running"}, "terminalCount": 0, "turns": [{"status": "running", "turn": "ROOT_TURN_1"}, {"status": "running", "turn": "ROOT_TURN_1"}], "type": "checkpoint"}
+{"lastError": "OpenCode event stream ended unexpectedly.", "status": "error", "type": "provider_session.updated"}
 {"ordinal": 1, "status": "failed", "turn": "ROOT_TURN_1", "type": "provider_turn.updated"}
-{"lastError": "Synthetic overflow O1", "status": "error", "type": "provider_session.updated"}
-{"failure": {"class": "provider_error", "code": "ContextOverflowError", "message": "Synthetic overflow O1", "retryable": null}, "failureItemOrdinal": 101, "runOrdinal": 1, "status": "failed", "threadDisposition": "reusable", "turn": "ROOT_TURN_1", "type": "turn.terminal"}
-{"label": "overflow-before-EOF", "session": {"lastError": "Synthetic overflow O1", "status": "error"}, "terminalCount": 1, "turns": [{"status": "running", "turn": "ROOT_TURN_1"}, {"status": "running", "turn": "ROOT_TURN_1"}, {"status": "failed", "turn": "ROOT_TURN_1"}], "type": "checkpoint"}
 {"lastError": "OpenCode event stream ended unexpectedly.", "status": "error", "type": "provider_session.updated"}
-{"terminalCount": 1, "terminals": [{"failure": {"class": "provider_error", "code": "ContextOverflowError", "message": "Synthetic overflow O1", "retryable": null}, "status": "failed", "threadDisposition": "reusable", "turn": "ROOT_TURN_1"}], "type": "capture-outcome"}
+{"failure": {"class": "transport_error", "code": null, "message": "OpenCode event stream ended unexpectedly.", "retryable": null}, "failureItemOrdinal": 101, "runOrdinal": 1, "status": "failed", "threadDisposition": "broken", "turn": "ROOT_TURN_1", "type": "turn.terminal"}
+{"terminalCount": 1, "terminals": [{"failure": {"class": "transport_error", "code": null, "message": "OpenCode event stream ended unexpectedly.", "retryable": null}, "status": "failed", "threadDisposition": "broken", "turn": "ROOT_TURN_1"}], "type": "capture-outcome"}