adjusted the dockerfile to make it work with nltk

Dockerfile

@@ -22,10 +22,16 @@ COPY requirements.txt .
 # Upgrade pip and install Python dependencies
 RUN pip install --upgrade pip
 RUN pip install --no-cache-dir -r requirements.txt
+# Pre-download NLTK resources
+RUN python -m nltk.downloader punkt_tab
+
 
 # Copy application code
 COPY . .
 
+# Tell NLTK where to find resources at runtime
+ENV NLTK_DATA=/usr/local/nltk_data
+
 # Expose port for FastAPI / Hugging Face Spaces
 EXPOSE 7860