pub fn place_spawn(block_id: &str, cmd: &mut Command, create: bool)Expand description
Make a child about to be spawned for block_id join its tracker before it
execs, so nothing it forks escapes between spawn and track_spawned
(Linux: the agent’s cgroup). create: start the block’s tracker if it has
none (an agent’s own CLI); otherwise join only an existing one (Shell(),
!cmd, like track_adopted). Still call track_spawned* /
track_adopted after the spawn: that records the PID and covers platforms
with no pre-exec placement.