Add production deployment configurations and guides

Deployment options:
- Railway cloud deployment (recommended, 5-min setup)
- Render alternative deployment
- Docker Compose for VPS deployment
- Comprehensive environment variable documentation

Includes:
- Production-grade Dockerfile with multi-stage builds
- Docker Compose configuration for production
- Detailed deployment guide with troubleshooting
- Backup and recovery procedures
- Monitoring and scaling recommendations

Deployment paths ready:
✅ Railway (railway.app)
✅ Render (render.com)
✅ Self-hosted VPS (DigitalOcean, Linode, etc.)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Dockerfile.prod

@@ -0,0 +1,32 @@
+# Build stage - backend
+FROM python:3.10-slim as backend-builder
+WORKDIR /app
+COPY backend/requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Runtime stage - backend
+FROM python:3.10-slim as backend
+WORKDIR /app
+COPY --from=backend-builder /usr/local/lib/python3.10/site-packages /usr/local/lib/python3.10/site-packages
+COPY backend /app
+ENV PYTHONUNBUFFERED=1
+EXPOSE 8000
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
+
+# Frontend build
+FROM node:22-alpine as frontend-builder
+WORKDIR /app
+COPY frontend/package*.json ./
+RUN npm ci
+COPY frontend .
+RUN npm run build
+
+# Frontend runtime
+FROM node:22-alpine as frontend
+WORKDIR /app
+COPY --from=frontend-builder /app/.next ./.next
+COPY --from=frontend-builder /app/node_modules ./node_modules
+COPY --from=frontend-builder /app/package*.json ./
+COPY frontend/public ./public
+EXPOSE 3000
+CMD ["npm", "start"]