The take-renderer-when-idle path never fired: capture_session_state_takeover_input
parsed active_renderer_id raw. The cloud encodes "nobody active" as -1, which was
read as Some(-1) and classified as a peer being active (OtherPaused), so
compute_connection_state returned should_set_active_renderer: false and the
auto-take was suppressed. Normalize identically to the apply path
(normalize_active_renderer_id filters >= 0 -> None) so -1 maps to
ServerActiveState::None and the idle auto-take claims the render. Adds the
auto_take_when_idle decision to compute_connection_state plus regression tests
for the -1 / active-peer classification.
cc