Replace stateful cache with atomic C controller

Dockerfile

@@ -1,12 +1,21 @@
-FROM ubuntu:24.04
-
+FROM ubuntu:24.04 AS build
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update \
- && apt-get install -y --no-install-recommends ca-certificates ffmpeg procps python3 util-linux \
+ && apt-get install -y --no-install-recommends \
+      build-essential pkg-config libcurl4-openssl-dev libjson-c-dev libxxhash-dev \
  && rm -rf /var/lib/apt/lists/*
+WORKDIR /src
+COPY Makefile pretranscode.c ./
+COPY tests ./tests
+RUN make check CFLAGS='-O2 -std=c17 -Wall -Wextra -Wpedantic -Werror -Wconversion -Wshadow -Wstrict-prototypes -Wmissing-prototypes -Wformat=2 -fstack-protector-strong'
 
-COPY pretranscode.py /app/pretranscode
-RUN chmod 0755 /app/pretranscode
-
-ENTRYPOINT ["nice","-n","19","ionice","-c","3","python3","/app/pretranscode"]
+FROM ubuntu:24.04
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+      ca-certificates ffmpeg libcurl4t64 libjson-c5 libxxhash0 procps \
+ && rm -rf /var/lib/apt/lists/*
+COPY --from=build /src/pretranscode /usr/local/bin/pretranscode
+USER 1000:1000
+ENTRYPOINT ["/usr/local/bin/pretranscode"]
 CMD ["run"]