stability_watchdog: remove SYS_WATCHDOG_FAILED_FILE from state file touch list — skip list is owned by docker_watchdog, not stability. docker_watchdog: rename check_system_watchdog_state → check_resource_watchdog_state (reads RW_STATE_FILE from resource_watchdog, not SYS_WATCHDOG_STATE_FILE from stability_watchdog). Update all comments and state file docs to reflect correct ownership. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>