Avoid race conditions on patch replenishment

[glopesdev]

This PR resolves two critical edge cases with patch replenishment:

1. Threshold crossing was using WithLatestFrom to get the current patch threshold. This means patch threshold transitions had to wait for a sample arriving from the wheel. This created a race between the block transition and local patch transition notifications. Changing the operator to CombineLatest ensures patch transition to NaN is synchronized and strictly preceding block transition.
2. If NaN threshold values end up in state recovery, it was impossible to resume patch operation since the sequence would never subscribe, and therefore could not be terminated to sample a new threshold. With the new synchronized patch transition behavior, this guard became unnecessary, and was removed.