v0.3.1-dev3

What's new

• Typed auth-failure surface. AuthenticationFailureException and ConnectionAttemptFailedException are now public top-level types. Consumers can catch them directly to distinguish auth failures from generic connection issues without inspecting the exception message string. The existing public AuthenticationFailure event continues to fire for callers that prefer the event-driven path.

This is a non-breaking change for the public API — both exception types were previously internal sealed and unreachable from outside the assembly, so no consumer can have been catching them by name before.

Why

Downstream consumers (StreamWeaver in particular) had to string-match Contains("auth") / Contains("credential") on ObsWebSocketException.Message to detect auth failures. Promoting the typed exceptions removes that fragility.