feat: consolidate backend and docker-compose setup

backend/scripts/run-demo.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+DEMO="${ROOT}/PaddleOCR-VL-1.6_Online_Demo"
+cd "$DEMO"
+
+unset VIRTUAL_ENV
+
+if [[ -f "${ROOT}/.env" ]]; then
+  set -a
+  # shellcheck disable=SC1091
+  source "${ROOT}/.env"
+  set +a
+fi
+
+PIPELINE_PORT="${PIPELINE_PORT:-8090}"
+GRADIO_PORT="${GRADIO_PORT:-7870}"
+export API_URL="${API_URL:-http://127.0.0.1:${PIPELINE_PORT}/layout-parsing}"
+
+echo "==> Starting PaddleOCR-VL-1.6 Online Demo"
+echo "    API_URL: ${API_URL}"
+echo "    Gradio:  http://127.0.0.1:${GRADIO_PORT}"
+
+if command -v ss >/dev/null 2>&1 && ss -tln | grep -q ":${GRADIO_PORT} "; then
+  echo "ERROR: Port ${GRADIO_PORT} is already in use." >&2
+  echo "  The demo may already be running — open http://127.0.0.1:${GRADIO_PORT}" >&2
+  echo "  To restart: stop the old process (e.g. fuser -k ${GRADIO_PORT}/tcp) then run this script again." >&2
+  echo "  Or use another port: GRADIO_PORT=7871 ./scripts/run-demo.sh" >&2
+  exit 1
+fi
+
+if [[ ! -d .venv ]]; then
+  echo "==> Creating demo venv and installing requirements"
+  uv venv .venv --python 3.12
+  uv pip install --python .venv -r requirements.txt
+fi
+
+export GRADIO_SERVER_PORT="${GRADIO_PORT}"
+export GRADIO_SERVER_NAME="127.0.0.1"
+export GRADIO_MCP_SERVER="True"
+
+exec uv run --no-project --python .venv/bin/python python app.py
+