Add Docker support and update README with deployment options

- Add Dockerfile with multi-stage build for production deployment
- Add docker-compose.yml for easy local development
- Add .dockerignore to optimize Docker build context
- Update README with Docker and local setup instructions

Dockerfile

@@ -0,0 +1,33 @@
+# Use Python 3.11 slim image as base
+FROM python:3.11-slim
+
+# Set working directory
+WORKDIR /app
+
+# Set environment variables
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    FLASK_APP=src/run.py
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    gcc \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy requirements first for better layer caching
+COPY requirements.txt .
+
+# Install Python dependencies
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY . .
+
+# Create necessary directories for runtime
+RUN mkdir -p src/app/static/images src/app/static/barcodes src/app/instance
+
+# Expose port 5555
+EXPOSE 5555
+
+# Run the application
+CMD ["python", "src/run.py"]