fix: create unit test directory structure and fix pytest-xprocess compatibility

Co-authored-by: 0xrinegade <[email protected]>

Author: Copilot

python/tests/integration/__init__.py

@@ -0,0 +1 @@
+"""Integration tests for solana_ai_registries package."""

python/tests/integration/test_devnet.py

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+"""Integration tests for devnet environment."""
+
+import pytest
+
+
+@pytest.mark.integration
+@pytest.mark.devnet
+def test_devnet_placeholder() -> None:
+    """Placeholder test for devnet integration."""
+    # This is a placeholder test that will be implemented
+    # as part of the SDK implementation tasks
+    pass

python/tests/unit/__init__.py

@@ -0,0 +1 @@
+"""Unit tests for solana_ai_registries package."""