Update dockerfile

dockerfile

@@ -1,11 +1,22 @@
-FROM python:3.9.18-slim-bullseye
+FROM python:3.11-slim-bullseye
 WORKDIR /app
-RUN apt-get update && apt-get -y upgrade && apt-get install -y ffmpeg
-RUN mkdir /app/data && mkdir /app/.streamlit
+
+# System packages needed for ffmpeg and yt‑dlp
+RUN apt-get update && apt-get -y upgrade && \
+    apt-get install -y ffmpeg && \
+    rm -rf /var/lib/apt/lists/*
+
+# Create folders used by the app
+RUN mkdir -p /app/data /app/.streamlit
+
+# Copy source files
 COPY requirements.txt /app/requirements.txt
 COPY .streamlit/config.toml /app/.streamlit/config.toml
 COPY streamlit_app.py /app
-RUN pip install --upgrade pip
-RUN pip install -r requirements.txt
+
+# Install Python deps
+RUN pip install --upgrade pip && \
+    pip install -r requirements.txt
+
 EXPOSE 8501
 CMD ["streamlit", "run", "streamlit_app.py", "--server.port", "8501"]