Add Dockerfile to trigger Docker Space build

Dockerfile

@@ -0,0 +1,26 @@
+FROM python:3.10-slim
+
+# Create a non-root user (required by Hugging Face Spaces)
+RUN useradd -m -u 1000 user
+USER user
+ENV HOME=/home/user \
+    PATH=/home/user/.local/bin:$PATH
+
+WORKDIR /home/user/app
+
+# Install dependencies
+COPY --chown=user requirements.txt ./requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Download NLTK data required by feature_extraction.py
+RUN python -c "import nltk; nltk.download('punkt'); nltk.download('stopwords'); nltk.download('wordnet'); nltk.download('punkt_tab')"
+
+# Copy application files
+COPY --chown=user . ./
+
+# Hugging Face Spaces exposes port 7860
+EXPOSE 7860
+ENV PORT=7860
+
+# Run with gunicorn for production
+CMD ["gunicorn", "--bind", "0.0.0.0:7860", "--workers", "1", "--timeout", "300", "app:app"]