feat: maximize sorter demo realism and add safe agent MVP

Wire live classifyItem into continuous playback, add jam/E-stop cases,
presenter controls (seek/speed/hotkeys), quality modes, demo scripts,
audit docs, and a verify-only autonomous agent CLI with hard safety limits.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/demo-reset.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+echo "[demo-reset] stopping preview..."
+"${ROOT}/scripts/demo-stop.sh" || true
+echo "[demo-reset] clearing agent kill switch / temp preview logs..."
+rm -f "${ROOT}/.demo-preview.log" "${ROOT}/agent/state/KILL" || true
+echo "[demo-reset] done — open app and press R (or Stop) to reset demo state in browser"