Based on the repository's commit message style and the changes in the diff, here's an appropriate commit message:

```
feat: add websocket tests, PoA metrics, marketplace endpoints, and enhanced observability

- Add comprehensive websocket tests for blocks and transactions streams including multi-subscriber and high-volume scenarios
- Extend PoA consensus with per-proposer block metrics and rotation tracking
- Add latest block interval gauge and RPC error spike alerting
- Enhance mock coordinator

packages/py/aitbc-crypto/src/aitbc_crypto.egg-info/PKG-INFO

@@ -0,0 +1,7 @@
+Metadata-Version: 2.4
+Name: aitbc-crypto
+Version: 0.1.0
+Summary: AITBC cryptographic utilities
+Requires-Python: >=3.11
+Requires-Dist: pydantic>=2.7.0
+Requires-Dist: pynacl>=1.5.0

packages/py/aitbc-crypto/src/aitbc_crypto.egg-info/SOURCES.txt

@@ -0,0 +1,13 @@
+pyproject.toml
+src/__init__.py
+src/receipt.py
+src/signing.py
+src/aitbc_crypto/__init__.py
+src/aitbc_crypto/receipt.py
+src/aitbc_crypto/signing.py
+src/aitbc_crypto.egg-info/PKG-INFO
+src/aitbc_crypto.egg-info/SOURCES.txt
+src/aitbc_crypto.egg-info/dependency_links.txt
+src/aitbc_crypto.egg-info/requires.txt
+src/aitbc_crypto.egg-info/top_level.txt
+tests/test_receipt_signing.py

packages/py/aitbc-crypto/src/aitbc_crypto.egg-info/dependency_links.txt

@@ -0,0 +1 @@
+

packages/py/aitbc-crypto/src/aitbc_crypto.egg-info/requires.txt

@@ -0,0 +1,2 @@
+pydantic>=2.7.0
+pynacl>=1.5.0

packages/py/aitbc-crypto/src/aitbc_crypto.egg-info/top_level.txt

@@ -0,0 +1,4 @@
+__init__
+aitbc_crypto
+receipt
+signing