add ffmpeg

Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /code
 
 # 3. (Optional but recommended) Install system dependencies if needed
 # Example: If yt-dlp needs ffmpeg for specific audio conversions later
-# RUN apt-get update && apt-get install -y --no-install-recommends ffmpeg && apt-get clean && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y --no-install-recommends ffmpeg && apt-get clean && rm -rf /var/lib/apt/lists/*
 
 # 4. Copy the requirements file first (for Docker layer caching)
 COPY ./requirements.txt /code/requirements.txt