Adopting a pre-bound socket via SetReservedListenSocket left Worker()'s
port bookkeeping untouched, so GetPort() and the broadcast announcement
reported the computed default instead of the port the socket listens on.
The monitor kept this correct by mirroring the reserved port into
TRACY_PORT; direct users of the public API had no such coupling.
The bound socket is now authoritative: Worker() reads the local port
back via getsockname after binding. The search-loop bookkeeping stays
only as a fallback for a getsockname failure.
