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/vanetza/geonet/tests/position_updater.cpp

@@ -0,0 +1,109 @@
+#include <gtest/gtest.h>
+#include <vanetza/common/manual_runtime.hpp>
+#include <vanetza/common/position_provider.hpp>
+#include <vanetza/geonet/mib.hpp>
+#include <vanetza/geonet/position_updater.hpp>
+#include <vanetza/geonet/router.hpp>
+#include <chrono>
+
+using namespace vanetza;
+using namespace vanetza::geonet;
+using namespace std::chrono;
+
+class IncrementalPositionProvider : public PositionProvider
+{
+public:
+    const PositionFix& position_fix() override
+    {
+        next_position();
+        return position;
+    }
+
+private:
+    void next_position()
+    {
+        ++updates;
+        position.latitude = updates * 3.0 * units::degree;
+        position.longitude = updates * -1.5 * units::degree;
+        position.confidence.semi_minor = 25.0 * units::si::meter;
+        position.confidence.semi_major = 25.0 * units::si::meter;
+    }
+
+    unsigned updates = 0;
+    PositionFix position;
+};
+
+class PositionUpdaterTest : public ::testing::Test
+{
+public:
+    PositionUpdaterTest() :
+        router(runtime, mib), updater(runtime, positioning, router)
+    {
+    }
+
+    void SetUp() override
+    {
+        mib.itsGnSecurity = false; /*< no security entity required */
+        mib.itsGnMinimumUpdateFrequencyEPV = 1.0 * units::si::hertz;
+    }
+
+    unsigned lpv_updates()
+    {
+        units::GeoAngle latitude { router.get_local_position_vector().latitude };
+        return latitude.value() / 3;
+    }
+
+protected:
+    ManualRuntime runtime;
+    MIB mib;
+    Router router;
+    IncrementalPositionProvider positioning;
+    PositionUpdater updater;
+};
+
+TEST_F(PositionUpdaterTest, default_update_rate)
+{
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(milliseconds(950));
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(milliseconds(60));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(2, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(3, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, custom_update_interval)
+{
+    updater.update_rate(seconds(10));
+    runtime.trigger(seconds(9));
+    EXPECT_EQ(0, lpv_updates());
+    runtime.trigger(seconds(1));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(seconds(10));
+    EXPECT_EQ(2, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, custom_update_frequency)
+{
+    updater.update_rate(4.0 * units::si::hertz);
+    runtime.trigger(milliseconds(250));
+    EXPECT_EQ(1, lpv_updates());
+    runtime.trigger(milliseconds(250));
+    EXPECT_EQ(2, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, zero_hertz)
+{
+    updater.update_rate(0.0 * units::si::hertz);
+    runtime.trigger(seconds(60));
+    EXPECT_EQ(0, lpv_updates());
+}
+
+TEST_F(PositionUpdaterTest, negative_interval)
+{
+    updater.update_rate(milliseconds(-200));
+    runtime.trigger(seconds(60));
+    EXPECT_EQ(0, lpv_updates());
+}