v0.3.3 - keepalive disabled (controller-hang A/B test)
A/B test build: TCP keepalive DISABLED.
The aggressive keepalive added from upstream (5s idle / 1s interval / 10s TCP_USER_TIMEOUT) is the prime suspect for the recurring overnight controller network hangs - the long-reliable original code set NO socket options. This build removes it; single-variable change vs 0.3.2.
If the early-morning hangs STOP on this build, the keepalive was the cause. If they continue, it points to the controller's own firmware.
All features unchanged: favourites select, console-temp sensor, dropout-fix ACKs, faster reconnect, unavailable-on-disconnect, 0xFD tolerance.