authoritative server OK

+ TODO actual matchmaking

src/client/constants.ts

@@ -5,3 +5,6 @@ export * from "../shared_js/constants.js"
 export	const midLineSize = Math.floor(w/150);
 export	const scoreSize = Math.floor(w/16); 
 export	const gridSize = Math.floor(w/500);
+
+// min interval on Firefox seems to be 15. Chrome can go lower.
+export	const gameLoopIntervalMS = 15; // millisecond