feat: homelab deployment - NPM + IONOS DNS + monitoring + NAS backup

- Restructured docker-compose for Nginx Proxy Manager (no custom nginx)
- Added domain wordly.art configuration
- Added Prometheus + Grafana monitoring stack with pre-configured dashboards
- Added PostgreSQL backup script to NAS (daily/weekly/monthly rotation)
- Added alert rules for backend, system, and Docker metrics
- Updated deployment guide for NPM + IONOS DNS homelab setup
- Added marketing plan document
- PDF translator and watermark support
- Enhanced middleware, routes, and translator modules

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker/backend/Dockerfile

@@ -26,11 +26,15 @@ FROM python:3.12-slim AS production
 
 WORKDIR /app
 
-# Install runtime dependencies only
+# Install runtime dependencies + LibreOffice headless (required for DOCX→PDF)
 RUN apt-get update && apt-get install -y --no-install-recommends \
     libmagic1 \
     libpq5 \
     curl \
+    fonts-noto \
+    fonts-noto-cjk \
+    fonts-noto-cjk-extra \
+    libreoffice-writer-nogui \
     && rm -rf /var/lib/apt/lists/* \
     && apt-get clean
 
@@ -38,8 +42,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 COPY --from=builder /opt/venv /opt/venv
 ENV PATH="/opt/venv/bin:$PATH"
 
-# Create non-root user for security
-RUN groupadd -r translator && useradd -r -g translator translator
+# Create non-root user with a proper home directory (LibreOffice needs it)
+RUN groupadd -r translator && \
+    useradd -r -g translator -m -d /home/translator translator && \
+    mkdir -p /home/translator/.cache && \
+    chown -R translator:translator /home/translator
 
 # Create necessary directories
 RUN mkdir -p /app/uploads /app/outputs /app/logs /app/temp \