Run integration tests in a single shared session

[jackwildman]

Summary

• Add a session-scoped pytest fixture in conftest.py that creates one shared everyrow session for all integration tests
• Update all 26 integration tests to use the shared session fixture instead of creating their own
• Add asyncio_default_fixture_loop_scope = "session" to pytest config for proper async fixture support

Test plan

• Run integration tests with pytest -m integration and verify only one session is created
• Check everyrow dashboard to confirm single session with timestamp name

🤖 Generated with Claude Code

[sentry]

Bug: The session-scoped async fixture runs in a different event loop than the tests, which will cause runtime errors because asyncio objects are not cross-loop compatible.
_{Severity: CRITICAL}

Suggested Fix

Add @pytest.mark.asyncio(loop_scope="session") to all integration test markers. Alternatively, implement a pytest_collection_modifyitems hook to automatically apply this marker to all async tests, ensuring they share the same event loop as the session-scoped fixture.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: tests/integration/conftest.py#L22-L28

Potential issue: The `pyproject.toml` configuration `asyncio_default_fixture_loop_scope
= "session"` only applies to fixtures, not the tests themselves. Since the integration
tests are not explicitly marked with `@pytest.mark.asyncio(loop_scope="session")`, they
will default to function-scoped event loops. This creates a mismatch where the shared
`Session` object, created in the session-scoped loop, is used across different
function-scoped loops. This is not permitted by asyncio and will lead to runtime errors
like `RuntimeError: Event loop is closed` when the tests attempt to use the async
client.

_{Did we get this right? 👍 / 👎 to inform future reviews.}