diff --git a/packages/agent-bundle/src/dev/workbench-server.ts b/packages/agent-bundle/src/dev/workbench-server.ts
index b3ec400f4..9584368c7 100644
--- a/packages/agent-bundle/src/dev/workbench-server.ts
+++ b/packages/agent-bundle/src/dev/workbench-server.ts
@@ -419,66 +419,34 @@ export const closeDevServerLifecycle = async ({
     producer: 'project',
     summary: 'Development workbench shutdown started.',
   });
-  const playgroundResults = playground === undefined ? [] : await Promise.allSettled([playground.close()]);
-  const appResults = mcpApps === undefined ? [] : await Promise.allSettled([mcpApps.close()]);
-  const clientSurfaceResults = runtimeResources?.clientSurfaces === undefined
-    ? []
-    : await Promise.allSettled([runtimeResources.clientSurfaces.close()]);
-  const runtimeResults = runtimeResources?.runtime === undefined
-    ? []
-    : await Promise.allSettled([runtimeResources.runtime.close()]);
-  const sessionResults = await Promise.allSettled([mcpSessions.close()]);
-  const coordinatorResults = await Promise.allSettled([coordinator.close()]);
+  // Producers close strictly in this order, each awaited before the next;
+  // the ordering is load-bearing for the sessions the coordinator drains.
+  const producers: readonly (readonly [DevServerLifecycleCloseFailure['resource'], Closeable | undefined])[] = [
+    ['playground', playground],
+    ['mcp-apps', mcpApps],
+    ['runtime-client-surfaces', runtimeResources?.clientSurfaces],
+    ['runtime', runtimeResources?.runtime],
+    ['mcp-sessions', mcpSessions],
+    ['coordinator', coordinator],
+  ];
+  const failures: DevServerLifecycleCloseFailure[] = [];
+  const closeResource = async (resource: DevServerLifecycleCloseFailure['resource'], closeable: Closeable): Promise<void> => {
+    const [result] = await Promise.allSettled([closeable.close()]);
+    if (result?.status === 'rejected') failures.push(Object.freeze({ error: result.reason, resource }));
+  };
+  for (const [resource, closeable] of producers) {
+    if (closeable !== undefined) await closeResource(resource, closeable);
+  }
   try { detachProjectLogs?.(); }
   catch { /* The subscription is observability-only and cannot hold shutdown. */ }
-  const producerFailures = [
-    ...playgroundResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'playground' as const })]
-        : [],
-    ),
-    ...appResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'mcp-apps' as const })]
-        : [],
-    ),
-    ...clientSurfaceResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'runtime-client-surfaces' as const })]
-        : [],
-    ),
-    ...runtimeResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'runtime' as const })]
-        : [],
-    ),
-    ...sessionResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'mcp-sessions' as const })]
-        : [],
-    ),
-    ...coordinatorResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'coordinator' as const })]
-        : [],
-    ),
-  ];
   logs?.log({
-    details: { failures: producerFailures.length },
+    details: { failures: failures.length },
     kind: 'dev.shutdown.completed',
-    level: producerFailures.length === 0 ? 'info' : 'warning',
+    level: failures.length === 0 ? 'info' : 'warning',
     producer: 'project',
-    summary: producerFailures.length === 0 ? 'Development workbench shutdown completed.' : 'Development workbench shutdown completed with failures.',
+    summary: failures.length === 0 ? 'Development workbench shutdown completed.' : 'Development workbench shutdown completed with failures.',
   });
-  const logsResults = logs === undefined ? [] : await Promise.allSettled([logs.close()]);
-  const failures = [
-    ...producerFailures,
-    ...logsResults.flatMap((result): readonly DevServerLifecycleCloseFailure[] =>
-      result.status === 'rejected'
-        ? [Object.freeze({ error: result.reason, resource: 'logs' as const })]
-        : [],
-    ),
-  ];
+  if (logs !== undefined) await closeResource('logs', logs);
   if (failures.length > 0) throw new DevServerLifecycleCloseError(failures);
 };
 
diff --git a/packages/workbench/src/main.tsx b/packages/workbench/src/main.tsx
index 969c8020e..775dcf964 100644
--- a/packages/workbench/src/main.tsx
+++ b/packages/workbench/src/main.tsx
@@ -852,7 +852,8 @@ const Workbench = () => {
   const [capabilityRetry, setCapabilityRetry] = useState(0);
   const [capabilityState, setCapabilityState] = useState<CapabilityState>({ state: 'empty' });
   if (foreground.current === undefined) foreground.current = new ForegroundRouteClient();
-  if (mcpRoutes.current === undefined) mcpRoutes.current = new WorkbenchMcpRouteClient({ foreground: foreground.current });
+  const foregroundClient = foreground.current;
+  if (mcpRoutes.current === undefined) mcpRoutes.current = new WorkbenchMcpRouteClient({ foreground: foregroundClient });
 
   const [mcpController, setMcpController] = useState(() => createMcpController(mcpRoutes.current!));
   const [mcpModel, setMcpModel] = useState(() => mcpController.model);
@@ -909,20 +910,20 @@ const Workbench = () => {
         setMcpController(replacement);
         setMcpModel(replacement.model);
       },
-      foreground: foreground.current!,
+      foreground: foregroundClient,
     });
   }
   if (mcpAppClient.current === undefined) {
-    mcpAppClient.current = new McpAppClient({ foreground: foreground.current!, projectClient: client.current });
+    mcpAppClient.current = new McpAppClient({ foreground: foregroundClient, projectClient: client.current });
   }
   if (mcpControllerRef.current !== mcpController) mcpControllerRef.current = mcpController;
-  if (runtimeClient.current === undefined) runtimeClient.current = new RuntimeClient(foreground.current);
-  if (artifactClient.current === undefined) artifactClient.current = new ArtifactClient({ foreground: foreground.current! });
-  if (comparisonClient.current === undefined) comparisonClient.current = new ComparisonClient({ foreground: foreground.current! });
-  if (evalClient.current === undefined) evalClient.current = new EvalClient({ foreground: foreground.current! });
-  if (hookClient.current === undefined) hookClient.current = new HookClient({ foreground: foreground.current! });
-  if (logClient.current === undefined) logClient.current = new LogClient({ foreground: foreground.current! });
-  if (playgroundClient.current === undefined) playgroundClient.current = new PlaygroundClient({ foreground: foreground.current! });
+  if (runtimeClient.current === undefined) runtimeClient.current = new RuntimeClient(foregroundClient);
+  if (artifactClient.current === undefined) artifactClient.current = new ArtifactClient({ foreground: foregroundClient });
+  if (comparisonClient.current === undefined) comparisonClient.current = new ComparisonClient({ foreground: foregroundClient });
+  if (evalClient.current === undefined) evalClient.current = new EvalClient({ foreground: foregroundClient });
+  if (hookClient.current === undefined) hookClient.current = new HookClient({ foreground: foregroundClient });
+  if (logClient.current === undefined) logClient.current = new LogClient({ foreground: foregroundClient });
+  if (playgroundClient.current === undefined) playgroundClient.current = new PlaygroundClient({ foreground: foregroundClient });
 
   const runtimeAvailable = runtimeCapability === 'available';
   const buildId = status === undefined ? undefined : activeEpochId(status);