Reduce calls to Init() in sound drivers

**Description**

Findings from the last ASIO4ALL bug fix showed that the Init() function might be called 4 times in the ASIO backend. This feels inefficient. I remember that iOS even refused to start due to having too many audio initialization calls.
We might need to rethink the sound design - not now but for after the review freeze.

Start by tracing the Init() calls in the ASIO backend and reviewing the iOS startup path mentioned in the issue. Identify why initialization can occur four times and define the expected single initialization lifecycle; done means redundant calls are reduced without preventing ASIO4ALL or iOS audio from starting.

Written by the indexing model from the issue text.