fix(project-files): recheck cancellation before completing a workbench upload

Provenance resolution can outlast the invocation; completion now rechecks both
signals before it registers the file, as the create path does.

Author: waleedlatif1

apps/sim/lib/mothership/agent-cli/project-file-upload-transport.ts

@@ -126,6 +126,7 @@ export function createProjectFileUploadTransport(
       if (!secretProvenance) {
         return v2Error('SERVICE_UNAVAILABLE', 'Workbench upload source has not finished streaming')
       }
+      throwIfCancelled(context.signal, request.signal)
       const result = await executeCopilotProjectFileUseCase(
         context,
         completeProjectFileUploadSession,