Under the hood
No documentation found
Bash commands now default to a 'shell' execution class that inserts a background-task join marker
What
Bash command execution now defaults its internal cgroup class (a grouping used to manage resource limits) to "shell". Whenever that class is "shell", a new shellToolCommand setting kicks in and causes the command builder to prepend a small marker command, referred to as a cc-shell join marker, before running the actual command.
Why
This appears to be internal plumbing for tracking or synchronizing background shell tasks; the finding doesn't specify what user-visible behavior depends on this marker.
Names in the bundlecc-shell
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
What the cc-shell join marker is used for downstream, and whether it's visible to users, isn't shown by the finding.