fix(docker): use host nginx, fix libgdk-pixbuf package name

- Update libgdk-pixbuf2.0-0 to libgdk-pixbuf-2.0-0 for Debian Trixie
- Remove bundled nginx container in favor of host nginx
- Use host networking for cloudflared to reach host nginx
- Expose streamlit on localhost:8080 for host nginx proxy

Dockerfile

@@ -6,7 +6,7 @@ WORKDIR /app
 RUN apt-get update && apt-get install -y --no-install-recommends \
     libpango-1.0-0 \
     libpangocairo-1.0-0 \
-    libgdk-pixbuf2.0-0 \
+    libgdk-pixbuf-2.0-0 \
     libffi-dev \
     shared-mime-info \
     && rm -rf /var/lib/apt/lists/*