After accomplishing Task 2, see Codex_Response... for details.

Codex_Response_3.md

@@ -0,0 +1,27 @@
+Task #2 completed in `/usr/local/src/reticulum/LXMF`.
+
+Created:
+
+- `tools/make_test_vectors.pl`
+- `tools/verify_examples.pl`
+- `tools/LXMF/MessagePack.pm`
+- `tools/README.md`
+- `examples/lxmf_message_minimal.hex`
+- `examples/lxmf_message_stamped.hex`
+- `examples/lxmf_message_vectors.json`
+
+The dependency-free Perl tooling verifies:
+
+- Fixed hash/signature positions
+- Payload order and MessagePack types
+- Message ID calculation
+- Optional stamp exclusion from message ID and signature input
+
+Validation passed:
+
+```text
+Reticulum umsgpack byte-for-byte cross-check passed
+All LXMessage test-vector checks passed.
+```
+
+The vectors regenerate deterministically. Signature bytes are documented placeholders; Ed25519 validation is not claimed. `SPEC.md` was not created or modified.