Keep vanetza-idf in obu-firmware, so a plain clone builds the firmware

obu-firmware builds against the vanetza-idf C-ITS library, which until now
came from the colleague's microbu-esp32c5 tree beside the repository and was
not tracked here, so a clone of this repository could not build the firmware
it ships. The library alone is now part of obu-firmware, as
obu-firmware/external/vanetza-idf: their external/vanetza-idf at commit
cf4b99f, unchanged (9775 files; see its PROVENANCE.md). CMake takes it from
there by default; -DVANETZA_IDF_DIR still points the build elsewhere.

The rest of the colleague's tree (their own VAM firmware, PKI tooling,
station-link Python tools, the V2X2MAP bridge) stays out of this repository
and gitignored; nothing is pushed to their repository. NOTES.md, docs/06,
TODO.md and the pcap verifier's usage line point at the new location.

obu-firmware/external/vanetza-idf/tools/docker/Dockerfile

@@ -0,0 +1,61 @@
+ARG DEBIAN_VERSION=stable
+ARG UBUNTU_VERSION=resolute
+
+FROM debian:${DEBIAN_VERSION} AS debian
+ARG DEBIAN_FRONTEND=noninteractive
+SHELL ["/bin/bash", "-c"]
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        build-essential \
+        ca-certificates \
+        capnproto \
+        clang \
+        cmake \
+        git \
+        libboost-date-time-dev \
+        libboost-program-options-dev \
+        libboost-system-dev \
+        libcapnp-dev \
+        libcrypto++-dev \
+        libgeographiclib-dev \
+        libssl-dev \
+        ninja-build \
+        pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+COPY --chmod=755 build_and_run_tests.sh build_strict_cxx14.sh /usr/local/bin/
+RUN useradd -m build-user
+USER build-user
+WORKDIR /home/build-user
+ENTRYPOINT ["build_and_run_tests.sh"]
+CMD ["/home/build-user/workspace"]
+
+FROM debian AS strict-cxx14
+ENTRYPOINT ["build_strict_cxx14.sh"]
+CMD ["/home/build-user/workspace"]
+
+FROM ubuntu:${UBUNTU_VERSION} AS ubuntu
+ARG DEBIAN_FRONTEND=noninteractive
+SHELL ["/bin/bash", "-c"]
+COPY --chmod=755 update_cmake.sh apt_pkg_name.sh /usr/local/bin/
+RUN update_cmake.sh && apt-get update && \
+    apt-get install -y --no-install-recommends \
+        build-essential \
+        ca-certificates \
+        capnproto \
+        cmake \
+        git \
+        libboost-date-time-dev \
+        libboost-program-options-dev \
+        libboost-system-dev \
+        libcapnp-dev \
+        libcrypto++-dev \
+        $(apt_pkg_name.sh geographiclib) \
+        libssl-dev \
+        ninja-build \
+        pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+COPY build_and_run_tests.sh /usr/local/bin/build_and_run_tests.sh
+RUN useradd -m build-user
+USER build-user
+WORKDIR /home/build-user
+ENTRYPOINT ["build_and_run_tests.sh"]
+CMD ["/home/build-user/workspace"]