fix(tests): switch to asyncio_mode=strict to prevent kuzu segfault

The segfault was caused by pytest-asyncio creating background event loops
for all tests when asyncio_mode=auto. Kuzu's C++ library conflicts with
these background threads, causing segfaults during test execution.

Solution:
- Switch asyncio_mode from auto to strict in both pytest.ini files
- Explicitly mark async test files with pytest.mark.asyncio:
  - tests/test_mcp_v2.py
  - tests/test_mcp_tools.py
  - tests/test_lancedb_e2e.py

This prevents pytest-asyncio from creating event loops for kuzu tests
while keeping asyncio working for tests that explicitly opt in.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: HumanBean17

pytest.ini

@@ -1,3 +1,3 @@
 [pytest]
-asyncio_mode = auto
+asyncio_mode = strict
 testpaths = tests

tests/pytest.ini

@@ -1,3 +1,3 @@
 [pytest]
-asyncio_mode = auto
+asyncio_mode = strict
 testpaths = .

tests/test_lancedb_e2e.py

@@ -30,6 +30,7 @@
         reason="set JAVA_CODEBASE_RAG_RUN_HEAVY=1 to run the cocoindex + LanceDB end-to-end test",
     ),
     pytest.mark.lance_e2e,
+    pytest.mark.asyncio,
 ]
 
 CAPABILITY_SMOKE_ROOT = Path(__file__).resolve().parent / "fixtures" / "capability_smoke"

tests/test_mcp_tools.py

@@ -1,6 +1,11 @@
 """Tool-surface assertions for the v2 MCP API."""
 from __future__ import annotations
 
+import pytest
+
+# Mark all async tests in this module to use asyncio
+pytestmark = pytest.mark.asyncio
+
 
 def _enum_sets(node: object) -> list[set[str]]:
     found: list[set[str]] = []

tests/test_mcp_v2.py

@@ -16,6 +16,9 @@
 
 from java_ontology import VALID_RESOLVE_REASONS
 
+# Mark all async tests in this module to use asyncio
+pytestmark = pytest.mark.asyncio
+
 from mcp_v2 import (
     Edge,
     NodeFilter,