labs 2/6 done

tech: chain reaction - blocks caught in explosions, explode
tech: shock wave reduces explosion damage by 30% (was 40%)

slime hazards now draw themselves in hazard.query()
I updated all the maps to remove hazard.draw()
    but maybe I missed one let me know if you find a buggy slime
laser hazards also draw themselves in hazard.opticalQuery()

2/6 rooms for new level.labs() are completed

js/spawn.js

@@ -1526,7 +1526,7 @@ const spawn = {
                 ctx.stroke();
                 ctx.beginPath();
                 ctx.arc(m.pos.x, m.pos.y, 40, 0, 2 * Math.PI);
-                ctx.fillStyle = "rgba(150,0,255,0.15)";
+                ctx.fillStyle = "rgba(150,0,255,0.1)";
                 ctx.fill();
             }