add adversarial RX session test suite (49 tests)

Intrusive tests for the RX session pipeline covering:
- slot lifecycle (new/advance/destroy with truncation)
- v1 golden vectors from Cyphal spec (heartbeat, NodeInfo 11-frame, array CAN FD)
- v1 golden vectors from v4 libcanard (DUCK, {1..14}, {0..99}, CRC split)
- v0 golden vectors from DroneCAN bus capture (MagField, gnss.Fix, pressure, temp)
- session lifecycle and admission (creation, reuse, TID timeout, iface failover)
- priority preemption (independent slots, same-priority replacement, all 8 prios)
- OOM and error paths (session OOM, slot OOM, bad CRC)
- session cleanup (stale/fresh, max timeout, triggered by start)
- edge cases (extent zero, exact extent, TID rollover, multi-source, all 7 kinds)
- regressions for the two previously fixed bugs (bool CRC, toggle assertion)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: pavel-kirienko

tests/CMakeLists.txt

@@ -101,6 +101,7 @@ gen_test_matrix(test_intrusive_util "src/test_intrusive_util.c")
 gen_test_matrix(test_intrusive_tx "src/test_intrusive_tx.c")
 gen_test_matrix(test_intrusive_rx "src/test_intrusive_rx.c")
 gen_test_matrix(test_intrusive_rx_admission "src/test_intrusive_rx_admission.c")
+gen_test_matrix(test_intrusive_rx_session "src/test_intrusive_rx_session.c")
 # API tests.
 gen_test_single(test_api_tx "${library_dir}/canard.c;src/test_api_tx.cpp")