[BUG] fit_predict_async silently drops coverage parameter — prediction intervals never returned for async jobs

[rupeshca007]

Summary

executor.fit_predict_async() has no coverage parameter in its signature (executor.py:249), but fit_predict_async_tool tries to pass coverage=coverage to it (fit_predict.py:183). The argument is silently dropped, and self.predict() is called without coverage (executor.py:343), so prediction intervals are never returned for async jobs even when explicitly requested.

Root Cause

fit_predict_async signature (executor.py:249):

async def fit_predict_async(self, handle_id, dataset, horizon=12, job_id=None):
    # no coverage param!