Diagnose the flaky test

Implement diagnose_flaky(test_record) — the record has booleans uses_time, uses_random_unseeded, shared_state, order_dependent: - returns (verdict, causes): 'flaky' when any cause fires, else 'sound' - causes are human-readable fixes in fixed order: time → 'reads the wall clock: inject a clock'; randomness → 'unseeded randomness: seed it'; shared state → 'shared state: give each test its own world'; order dependence → 'order-dependent: construct prerequisites in the test' Mechanized triage: the reviewer's first five minutes, as a function.

Difficulty: advanced