Fix cache directory permissions for model downloading

Dockerfile

@@ -6,6 +6,12 @@ RUN apt-get update && apt-get install -y \
     build-essential \
     && rm -rf /var/lib/apt/lists/*
 
+RUN mkdir -p /app/.cache && chmod 777 /app/.cache
+
+ENV HF_HOME=/app/.cache
+ENV TRANSFORMERS_CACHE=/app/.cache/transformers
+ENV SENTENCE_TRANSFORMERS_HOME=/app/.cache/sentence-transformers
+
 COPY requirements.txt .
 
 RUN pip install --no-cache-dir -r requirements.txt