/review, the retention loop

Read skills/_shared/dialogue-grammar.md (hard rules, confidence integrity, park-and-resume, and the rating map apply here verbatim). Set:

# Resolve the engine. RUN THIS BLOCK VERBATIM, do not substitute a path you guessed.
# Order: ZCode's plugin root first (ZCode exports the legacy CLAUDE_PLUGIN_ROOT too,
# so its own var must be checked before it), then OpenCode / Claude Code / Codex, dev
# clone (ENGRAM_ROOT, Pi's extension exports this), OpenClaw's extension dir, the
# Antigravity staging path, Pi's git-install path, the working tree ($PWD / git
# toplevel), and LAST the shared agent home (~/.agents/engram, the clone route for
# platforms that read ~/.agents; last so it can shadow nothing). First one exists wins.
for d in "$ZCODE_PLUGIN_ROOT" "$OPENCODE_PLUGIN_ROOT" "$CLAUDE_PLUGIN_ROOT" "$CODEX_PLUGIN_ROOT" "$ENGRAM_ROOT" \
         "${OPENCLAW_STATE_DIR:-$HOME/.openclaw}/extensions/engram" \
         "$HOME/.gemini/config/plugins/engram" \
         "$HOME/.pi/agent/git/github.com/nagisanzenin/engram" \
         "$PWD" "$(git rev-parse --show-toplevel 2>/dev/null)" \
         "$HOME/.agents/engram"; do
  [ -n "$d" ] && [ -f "$d/scripts/engram.py" ] && ENGRAM="$d/scripts/engram.py" && break
done
if [ -z "$ENGRAM" ]; then
  echo "engram: engine not found, set ENGRAM_ROOT to your engram checkout" >&2
  return 2 2>/dev/null || exit 2   # FAIL CLOSED: proceeding runs `python3 ""`,
fi                                  # which dumps a python usage error at the learner

If none are set, resolve the plugin root as the directory containing .zcode-plugin/plugin.json, .claude-plugin/plugin.json, or .codex-plugin/plugin.json. Never inline a learner's answer into a shell command, pass productions via --production-file (or --production-file - on stdin); a stray quote or $(…) in what they typed would otherwise execute.