Update Dockerfile

Dockerfile

@@ -25,8 +25,8 @@ COPY requirements.txt .
 # Install Python dependencies
 RUN pip install --no-cache-dir -r requirements.txt
 
-# Pre-download NLTK punkt data to avoid runtime permission issues
-RUN python -m nltk.downloader -d /app/nltk_data punkt
+# Pre-download NLTK data (punkt and punkt_tab for compatibility)
+RUN python -m nltk.downloader -d /app/nltk_data punkt punkt_tab
 
 # Copy application code
 COPY app/main.py ./app/main.py