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/position_updater.hpp

@@ -0,0 +1,56 @@
+#ifndef POSITION_UPDATER_HPP_KMWXTJRO
+#define POSITION_UPDATER_HPP_KMWXTJRO
+
+#include <vanetza/common/clock.hpp>
+#include <vanetza/units/frequency.hpp>
+
+namespace vanetza
+{
+
+// forward declarations
+class Runtime;
+class PositionProvider;
+namespace geonet { class Router; }
+
+namespace geonet
+{
+
+/**
+ * PositionUpdater helps updating a Router's position vector periodically
+ */
+class PositionUpdater
+{
+public:
+    /**
+     * Create PositionUpdater scheduling position updates read from position provider
+     * \note the default update rate is derived from router's MIB.
+     * \param runtime where updater schedules its callback
+     * \param pos position updates are read from this source
+     * \param router position sink
+     */
+    PositionUpdater(Runtime& runtime, PositionProvider& pos, Router& router);
+    ~PositionUpdater();
+
+    /**
+     * Change rate at which update is looking up new positions
+     * \note MIB setting is not affected
+     * \note an update interval smaller than zero disables updates
+     * \param interval update interval
+     */
+    void update_rate(Clock::duration interval);
+    void update_rate(units::Frequency);
+
+private:
+    void schedule();
+
+    Runtime& m_runtime;
+    PositionProvider& m_positioning;
+    Router& m_router;
+    Clock::duration m_interval;
+};
+
+} // namespace geonet
+} // namespace vanetza
+
+#endif /* POSITION_UPDATER_HPP_KMWXTJRO */
+