Add SaaS AI engine (#5907)

engine/Dockerfile

@@ -0,0 +1,63 @@
+# syntax=docker/dockerfile:1.5
+FROM ghcr.io/astral-sh/uv:python3.13-bookworm-slim
+
+# Install system deps: Node.js + Puppeteer/Chromium runtime libraries
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+      ca-certificates \
+      poppler-utils \
+      nodejs \
+      npm \
+      # Fonts for correct text rendering in generated PDFs
+      fonts-liberation \
+      fonts-dejavu-core \
+      # Chromium headless runtime deps
+      libnss3 \
+      libatk1.0-0 \
+      libatk-bridge2.0-0 \
+      libcups2 \
+      libxkbcommon0 \
+      libxcomposite1 \
+      libxdamage1 \
+      libxrandr2 \
+      libpango-1.0-0 \
+      libcairo2 \
+      libasound2 \
+      libx11-6 \
+      libxext6 \
+      libxfixes3 \
+      libgbm1 \
+      libdrm2 \
+      libxshmfence1 \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Install Node dependencies (Puppeteer) first for layer caching
+COPY package.json package-lock.json ./
+RUN npm ci
+
+# Install Python dependencies
+COPY pyproject.toml uv.lock ./
+RUN --mount=type=cache,target=/root/.cache/uv \
+    uv sync --frozen --no-dev
+
+# Copy Python source into /app/src/
+COPY src/ ./src/
+
+# Create output directories
+RUN mkdir -p /app/output /app/data
+
+# Expose port
+EXPOSE 5001
+
+# Environment variables for Gunicorn configuration
+ENV GUNICORN_WORKERS=4
+ENV GUNICORN_TIMEOUT=120
+# Disable Python stdout/stderr buffering so log output appears immediately in Docker logs
+ENV PYTHONUNBUFFERED=1
+
+ENV PATH="/app/.venv/bin:$PATH"
+WORKDIR /app/src
+CMD ["sh", "-c", "gunicorn --bind 0.0.0.0:5001 --workers ${GUNICORN_WORKERS} --timeout ${GUNICORN_TIMEOUT} --worker-class gthread --threads 4 app:app"]