A loaded world starts around the player first, the rest a few areas a tick (t21)

- Areas within 150 grains of the bot start at once; the others 12 a tick, nearest first, and any
  the bot flies toward start straight away. A Huge world is fully started after 17 s.
- Huge world, first 600 ticks: average 15.2 -> 5.5 ms/tick, worst 79.7 -> 16.2.
- New test/t_load.js.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/sim/tick.js

@@ -3,6 +3,7 @@
 function simTick() {
   tick++;
   tickStamp = (tickStamp % 255) + 1;
+  if (loadWakeOrder) loadWakeTick();
   if (tick % 20 === 1) updateDirtyRoof();
   weatherTick();
   machinesTick();