fix: harden review and verifier governance

scripts/verify_phase4_echarts_gate_test.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT_DIR"
+
+python3 - <<'PY'
+from pathlib import Path
+text = Path('frontend/src/pages/Dashboard.tsx').read_text()
+assert 'echarts.init' in text, 'dashboard missing echarts.init usage'
+assert 'import * as echarts from "echarts"' in text or "import * as echarts from 'echarts'" in text, 'dashboard missing echarts import'
+PY