Privilege escalation via missed exec completion classification

Privilege escalation in OpenClaw before 2026.4.10 allows remote attackers to keep agent runs in a privileged owner context. The isExecCompletionEvent function in src/infra/heartbeat-events-filter.ts recognizes only exec-finished text, so local background events formatted as Exec completed or Exec failed bypass heartbeat owner-downgrade detection. Untrusted completion content must reach an affected run; the missed classification preserves access to data and actions available to the higher-privilege context.