Per-group max_idle

[moodmosaic]

max_idle is top-level only. Agents that naturally idle more than others (evaluators polling for output, reconciliation agents) hit the limit and exit before generators produce anything.

The idle counter checks whether origin/agent-work moved during the session. For short-lived sessions this is effectively per-agent — the session finishes before any other agent has pushed:

BEFORE=$(git rev-parse origin/agent-work)
# ... agent session (poll, find nothing, exit) ...
git fetch origin
AFTER=$(git rev-parse origin/agent-work)
if [ "$BEFORE" = "$AFTER" ]; then
    IDLE_COUNT=$((IDLE_COUNT + 1))

Per-group override:

{
  "max_idle": 5,
  "agents": [
    { "count": 3, "model": "claude-opus-4-6", "prompt": "build.md" },
    { "count": 1, "model": "claude-opus-4-6", "prompt": "review.md", "max_idle": 20 }
  ]
}

launch.sh reads the per-group value and passes it as MAX_IDLE to that container, falling back to the top-level default. Zero change to harness.sh.

Motivated by @anthropics' harness design post which runs an evaluator alongside generators — the evaluator needs a longer idle tolerance than the generators it monitors.