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-start.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+
+echo "[demo-start] installing deps if needed..."
+if [[ ! -d node_modules ]]; then
+  npm ci
+fi
+
+echo "[demo-start] building production bundle..."
+npm run build
+
+PID_FILE="${ROOT}/.demo-preview.pid"
+if [[ -f "$PID_FILE" ]] && kill -0 "$(cat "$PID_FILE")" 2>/dev/null; then
+  echo "[demo-start] preview already running (pid $(cat "$PID_FILE"))"
+  exit 0
+fi
+
+echo "[demo-start] starting vite preview on 127.0.0.1:3101 (dev preview; prod may already be on :3100)..."
+nohup npm run preview -- --host 127.0.0.1 --port 3101 > "${ROOT}/.demo-preview.log" 2>&1 &
+echo $! > "$PID_FILE"
+sleep 2
+curl -sf "http://127.0.0.1:3101/" >/dev/null && echo "[demo-start] OK http://127.0.0.1:3101/" || {
+  echo "[demo-start] preview not ready yet — check .demo-preview.log"
+  exit 1
+}