Sub-slice of #115. Port the develop-mode DAG walk (Blocked-by/Part-of frontier, MAX_PARALLEL concurrent worktree engineers, branch merge) out of the orchestrator prompt into the harness. The other half of the orchestrator. Blocked by #120. See amico-plugin#29 (the CC-side root-session invariant) — this is the amicode-side re-home.
Sub-slice of #115. Port the develop-mode DAG walk (Blocked-by/Part-of frontier, MAX_PARALLEL concurrent worktree engineers, branch merge) out of the orchestrator prompt into the harness. The other half of the orchestrator. Blocked by #120. See amico-plugin#29 (the CC-side root-session invariant) — this is the amicode-side re-home.