Add export tests for package-level __all__ symbols

Add test_package_exports.py: 3 tests verifying every symbol in __all__
is importable from PowerPlatform.Dataverse.{core,models,operations}.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash

tests/unit/test_package_exports.py

@@ -0,0 +1,42 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+
+"""Tests that every symbol in __all__ is importable from each package namespace."""
+
+import unittest
+
+
+class TestCoreExports(unittest.TestCase):
+    """Every name in PowerPlatform.Dataverse.core.__all__ must be importable."""
+
+    def test_all_symbols_importable(self):
+        import PowerPlatform.Dataverse.core as m
+
+        for name in m.__all__:
+            self.assertTrue(hasattr(m, name), f"{name!r} is in __all__ but missing from PowerPlatform.Dataverse.core")
+
+
+class TestModelsExports(unittest.TestCase):
+    """Every name in PowerPlatform.Dataverse.models.__all__ must be importable."""
+
+    def test_all_symbols_importable(self):
+        import PowerPlatform.Dataverse.models as m
+
+        for name in m.__all__:
+            self.assertTrue(hasattr(m, name), f"{name!r} is in __all__ but missing from PowerPlatform.Dataverse.models")
+
+
+class TestOperationsExports(unittest.TestCase):
+    """Every name in PowerPlatform.Dataverse.operations.__all__ must be importable."""
+
+    def test_all_symbols_importable(self):
+        import PowerPlatform.Dataverse.operations as m
+
+        for name in m.__all__:
+            self.assertTrue(
+                hasattr(m, name), f"{name!r} is in __all__ but missing from PowerPlatform.Dataverse.operations"
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()