Add optimized tutorial cover images

Dockerfile

@@ -16,6 +16,9 @@ FROM node:22-bookworm-slim AS runtime
 WORKDIR /app
 ENV NODE_ENV=production
 RUN corepack enable
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends ca-certificates ffmpeg \
+  && rm -rf /var/lib/apt/lists/*
 COPY package.json pnpm-lock.yaml ./
 COPY patches ./patches
 RUN pnpm install --prod --frozen-lockfile