[BUG] fix _score_params + add tests + fix errors 'masked' by the 'try... except'-block

[SimonBlanke]

Bug fix: _score_params passed parameters incorrectly

_score_params called experiment(**params), unpacking the dict as keyword arguments. BaseExperiment.__call__ expects a single positional dict, so every call raised a TypeError that was silently swallowed by the bare except clause. All candidates received error_score (NaN) and np.argmax always picked index 0, making optimization results appear stable but entirely meaningless.

Fixed by changing experiment(**params) to experiment(params). The except clause now also emits a warnings.warn so caught exceptions are no longer silent.

Fix: deterministic test parameters for TSCOptCV

The corrected _score_params exposed non-determinism in TSCOptCV.get_test_params: the "stratified" DummyClassifier strategy produces random predictions, and the default CV used shuffle=True without a fixed seed. Together these caused test_fit_idempotent to fail intermittently.

Fixed by replacing "stratified" with "prior" (deterministic) and pinning cv=KFold(n_splits=2, shuffle=False).

Enhancement: _predict_proba override for TSCOptCV

TSCOptCV overrode _predict with a refit=False guard but left _predict_proba unoverridden. With refit=False, predict raised RuntimeError while predict_proba silently delegated to an unfitted estimator. Added the same guard to _predict_proba.

Tests

Added unit tests for _score_params covering correct dict passing, return type, error score fallback, and warning emission.