findOctaviusCause

Finds the Octavius failure behind this throwable, if there is one.

A driver failure that crosses a JDBC boundary rarely arrives as itself. A connection pool restates it as an SQLException of its own, a framework restates that one in turn, and what the caller finally catches names only the layer it came from - HikariCP reporting a borrow that timed out says nothing about the server refusing the connection underneath it. The chain still carries the original, either as a SQLExceptionWrapper put there by the driver's JDBC surface or as a bare OctaviusException recorded by a pool that was trying to open a connection, so anything restating a foreign failure looks for the real one here before inventing its own.

The receiver itself is examined first, so a driver exception passed in directly is returned as it stands.