Add protocol-certification M8 DDR instance grouping (2.70.0).

Controller-aware per-memory instances, DQ/DQS vs addr/cmd/ctrl/ck, HBM not classic DDR PCB DQ. No universal mm/ps. No M6 packs, no L3 solver.

tests/pcb/test_protocol_l2_m4.py

@@ -205,7 +205,7 @@ def test_axi_internal_l2_not_applicable():
     assert all(r.result == "NOT_APPLICABLE" for r in rows)
     sec, findings = protocol_exam(_axi_graph())
     assert sec.max_level_reached == "L2"
-    assert sec.macrophase == "M5"
+    assert sec.macrophase == "M8"
     assert all(f.status != "ERROR" for f in findings)
     blob = json.dumps([r.model_dump() for r in rows])
     assert "L0/L1 are not electrical" in blob