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/pki/main.hpp

@@ -0,0 +1,40 @@
+#pragma once
+
+#include "certificate_storage.hpp"
+#include "credential_storage.hpp"
+#include "crl_store.hpp"
+#include "filesystem.hpp"
+#include "hashed_id8.hpp"
+#include "security_module.hpp"
+#include "station_config.hpp"
+#include "trust_list_storage.hpp"
+#include <memory>
+
+namespace vanetza
+{
+namespace pki
+{
+
+struct MainConfig
+{
+    std::filesystem::path config_path;
+    std::filesystem::path data_path;
+    std::string dc_url;
+    HashedId8 root_ca_hid8;
+    std::shared_ptr<StationConfiguration> station;
+    std::shared_ptr<SecurityModule> security;
+    std::shared_ptr<CertificateStorage> root_ca; // root CA certificates
+    std::shared_ptr<CertificateStorage> enrolment_credentials; // station's EC certificates
+    std::shared_ptr<CertificateStorage> tickets; // station's authorization tickets
+    std::shared_ptr<CertificateStorage> tlm; // trust list manager certificates
+    std::shared_ptr<CertificateStorage> authorization_authorities; // AA certs extracted from CTLs
+    std::shared_ptr<CertificateStorage> enrolment_authorities; // EA certs extracted from CTLs
+    std::shared_ptr<CredentialStorage> credentials; // private keys
+    std::shared_ptr<TrustListStorage> trust_lists;
+    std::shared_ptr<CrlFilesystemStore> crl_store; // certificate revocation lists
+};
+
+boost::optional<std::string> lookup_dc_url(const std::filesystem::path& ectl_file, const HashedId8& root_ca);
+
+} // namespace pki
+} // namespace vanetza