test: add pytest suite for pose utilities

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

py_workspace/tests/conftest.py

@@ -0,0 +1,6 @@
+import sys
+import os
+
+# The pytest console script does not always add the current working directory to sys.path.
+# This ensures that the 'aruco' module and other local packages are importable during tests.
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))