fix: sync fixture for alembic stamp, E2E CI race fix, ruff I rule removal

- Rewrite setup_database fixture to use sync engine with alembic stamp
- Fix E2E CI race condition (test-e2e depends on test-integration)
- Remove ruff I rule to resolve isort conflict

pyproject.toml

@@ -82,7 +82,7 @@ target-version = "py313"
 line-length = 100
 
 [tool.ruff.lint]
-select = ["E", "F", "I", "W", "B", "C4", "SIM"]
+select = ["E", "F", "W", "B", "C4", "SIM"]
 ignore = ["E501"]
 
 [tool.isort]