Dispatch — spawn a confined worker

One spawn shape, for every harness. The drive cadence lives in the /dispatch router; this skill is the spawn call plus the landing mechanics.

See lib:reference/dispatch-mechanics.md § The worker returns a working tree, not a commit.

Spawn

scripts/spawn-confined.sh <harness> <B> <BRANCH> <DIR> <PROMPT_FILE> [BACKSTOP_SECS]

<harness> is pi or claude. The script does the whole pre-spawn sequence itself — you do not fork separately: