Improve test import resilience and skip missing organchip deps

[STLNFTART]

Summary

• add repository root to pytest pythonpath for top-level organ chip packages
• ensure organ chip toxicity tests inject root/src paths and skip when organchip packages are unavailable

Testing

• pytest (fails: expected integration/model assertions and missing optional modules; see log)

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Project	Deployment	Preview	Comments	Updated (UTC)
multi-heart-model	Ready	Preview	Comment	Nov 27, 2025 5:44pm

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Avoid unpacking single-value simulate_drug_exposure

The new test unpacks simulate_drug_exposure into two variables, but OrganChipSuite.simulate_drug_exposure returns only a trajectory list, so this call will throw ValueError: not enough values to unpack before any assertions run. The same unpacking pattern is repeated in test_acetaminophen_gsh_depletion and test_circulation_distribution, meaning these tests will always error when pytest runs rather than exercising the toxicity logic.

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