fix: keep Workbench turn timing command-scoped (#1899)

internal/cloud/workbench-projection-writer.ts

@@ -108,7 +108,7 @@ export async function writeWorkbenchProjectionEvent({ runtimeStore = null, event
   const status = terminal ? normalizeWorkbenchStatus(event.status) : "running";
   const previousCheckpoint = await latestWorkbenchCheckpoint(runtimeStore, traceId);
   const previousTiming = normalizeTimingProjection(previousCheckpoint?.timing) ?? normalizeTimingProjection(previousCheckpoint);
-  const explicitStartedAt = optionalTimestampValue(event.startedAt ?? event.traceStartedAt ?? event.runnerStartedAt ?? event.agentRun?.startedAt);
+  const explicitStartedAt = optionalTimestampValue(event.startedAt ?? event.traceStartedAt ?? event.runnerStartedAt);
   const startedAt = explicitStartedAt ?? previousTiming?.startedAt ?? (sourceSeq <= 1 ? occurredAt : null);
   const lastEventAt = latestTimestamp(previousTiming?.lastEventAt, occurredAt, projectedAt);
   const finishedAt = terminal ? latestTimestamp(previousTiming?.lastEventAt, optionalTimestampValue(event.finishedAt), occurredAt, projectedAt) : null;

internal/cloud/workbench-turn-projection.ts

@@ -63,7 +63,6 @@ export function createWorkbenchTurnTimingProjection({ result = null, session = n
     result?.traceStartedAt,
     trace?.startedAt,
     traceSummary?.startedAt,
-    agentRun?.startedAt,
     firstEvent?.startedAt,
     firstEvent?.createdAt,
     firstEvent?.occurredAt
@@ -85,7 +84,6 @@ export function createWorkbenchTurnTimingProjection({ result = null, session = n
     directTiming?.finishedAt,
     trace?.finishedAt,
     traceSummary?.finishedAt,
-    agentRun?.finishedAt,
     trace?.terminalEvidence?.updatedAt,
     terminalEvent?.updatedAt,
     terminalEvent?.createdAt,
@@ -99,7 +97,6 @@ export function createWorkbenchTurnTimingProjection({ result = null, session = n
     directTiming?.durationMs,
     trace?.durationMs,
     traceSummary?.durationMs,
-    agentRun?.durationMs,
     trace?.elapsedMs,
     result?.elapsedMs,
     elapsedBetween(startedAt, finishedAt ?? lastEventAt)