feat: harden sync flow, proxy bridge, and data normalization

Dockerfile

@@ -5,6 +5,10 @@ ENV PYTHONDONTWRITEBYTECODE=1 \
 
 WORKDIR /app
 
+# Xvfb for headed Chromium in container (IAAI blocks headless)
+RUN apt-get update -qq && apt-get install -y --no-install-recommends xvfb \
+    && rm -rf /var/lib/apt/lists/*
+
 COPY requirements.txt ./
 RUN pip install --no-cache-dir -r requirements.txt