fix: use setsid for herdr server bootstrap to prevent early termination when parent shell exits

.agents/skills/lib.sh

@@ -117,7 +117,7 @@ except Exception:
     # Headless bootstrap avoids herdr's "nested herdr is disabled" guard that
     # blocks a normal interactive `herdr --session <name>` launch from inside
     # an existing herdr pane (which is how MAM's own agents usually run).
-    nohup "$REAL_HERDR" --session "$_MAM_SESSION" server >/dev/null 2>&1 &
+    setsid "$REAL_HERDR" --session "$_MAM_SESSION" server </dev/null >/dev/null 2>&1 &
     disown 2>/dev/null || true
     for _mam_wait_i in $(seq 1 40); do
       [ -S "${HOME:-$HOME_DIR}/.config/herdr/sessions/$_MAM_SESSION/herdr.sock" ] && break