The VNC desktop faded to black after weston's default 300s idle
timeout, and on wake desktop-shell showed its click-to-unlock lock
screen (a green circle) — pointless for an agent desktop viewed
over /screen, and confusing for the operator (issue #180).
Add [core] idle-time=0 to the generated weston.ini. Verified against
weston 14.0.1: idle-time parses to compositor->idle_time, and
weston_compositor_wake arms the idle timer with idle_time*1000 ms;
0 ms makes wl_event_source_timer_update disarm the timer, so the
compositor never transitions to IDLE and desktop-shell never locks.
closes#180
dd32774e86