Added docker functionality.

Dockerfile

@@ -0,0 +1,27 @@
+# Dockerfile for SWIPER image-swipe application
+# ------------------------------------------------
+# This image runs the built-in Python HTTP server provided by server.py.
+# Pillow needs system libs so we install them via apt.
+
+FROM python:3.11-slim
+
+# Install system packages required by Pillow (JPEG, zlib)
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends build-essential libjpeg-dev zlib1g-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set work directory
+WORKDIR /app
+
+# Install Python dependencies first (leverages Docker layer caching)
+COPY requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application source
+COPY . .
+
+# Expose the default port
+EXPOSE 8888
+
+# Start the server
+CMD ["python", "server.py"]