feat: Docker Hub image, cloaktest CLI, and example UX improvements

Add cloakhq/cloakbrowser Docker Hub image with Node.js, JS wrapper,
Xvfb headed mode, and cloaktest shortcut. Add launch feedback and IP
display to all examples. Update README Docker section for Docker Hub.

Dockerfile

@@ -1,6 +1,6 @@
 FROM python:3.12-slim
 
-# Chromium system deps (matches fingerprint-chromium 142+ requirements)
+# Chromium system deps + Node.js
 RUN apt-get update && apt-get install -y --no-install-recommends \
     libnss3 libnspr4 libatk1.0-0 libatk-bridge2.0-0 libcups2 \
     libdbus-1-3 libdrm2 libxkbcommon0 libatspi2.0-0 libxcomposite1 \
@@ -9,17 +9,38 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     libxcb1 libxext6 libxshmfence1 \
     libglib2.0-0 libgtk-3-0 libpangocairo-1.0-0 libcairo-gobject2 \
     libgdk-pixbuf-2.0-0 libxss1 libxtst6 fonts-liberation \
+    xvfb xdotool \
+    curl ca-certificates \
+    && curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
+    && apt-get install -y --no-install-recommends nodejs \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
 
+# Python wrapper
 COPY pyproject.toml README.md LICENSE BINARY-LICENSE.md CHANGELOG.md ./
 COPY cloakbrowser/ cloakbrowser/
-COPY examples/ examples/
-
 RUN pip install --no-cache-dir .
 
+# JS wrapper
+COPY js/ js/
+RUN cd js && npm install && npm run build
+
+# Examples
+COPY examples/ examples/
+
 # Pre-download stealth Chromium binary during build (not at runtime)
 RUN python -c "from cloakbrowser import ensure_binary; ensure_binary()"
 
+# CLI shortcuts
+COPY bin/cloaktest /usr/local/bin/cloaktest
+RUN chmod +x /usr/local/bin/cloaktest
+
+# Xvfb entrypoint for headed mode support
+COPY bin/docker-entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+ENV DISPLAY=:99
+
+ENTRYPOINT ["/entrypoint.sh"]
 CMD ["python"]