Add test run CLIs

Author: kdeldycke

tests/test_stream_lifecycle.py

@@ -14,6 +14,27 @@
 4. Multi-threaded safety: concurrent threads don't cause I/O-on-closed-file
 5. Sequential invocations: multiple ``invoke()`` calls don't corrupt state
 6. Stress tests (marked ``stress``): high-iteration reproducers for races
+
+How to run locally
+------------------
+
+Standard tests (fast, ~0.8s) with stress tests excluded by default:
+
+.. code-block:: shell-session
+
+    $ pytest tests/test_stream_lifecycle.py -v
+
+Stress tests only (30k iterations, ~52min):
+
+.. code-block:: shell-session
+
+    $ pytest tests/test_stream_lifecycle.py -m stress -x --override-ini="addopts="
+
+Everything:
+
+.. code-block:: shell-session
+
+    $ pytest tests/test_stream_lifecycle.py --override-ini="addopts=" -x
 """
 
 from __future__ import annotations