Append +artifact.<sha256> to the llama.cpp runtime axis, computed from the
exact bytes read by attest_loaded_runtime, so a differently-built shared
object with copied lock values can no longer forge a certified runtime
identity. Node/tracker parsers require the suffix; new test proves a
byte-identical-lock but different-binary artifact produces a different
recipe fingerprint. Regenerates conformance vectors accordingly.
105 passed in tests/test_native_identity_emission.py,
tests/test_runtime_pin_identity.py, tests/test_runtime_recipe_identity.py.
