Remember focus between tests

src/server/pause.js

@@ -134,7 +134,7 @@ runBtn.addEventListener('click', run);
 const testName = document.querySelector('#test-name');
 
 /* eslint-disable no-undef, no-invalid-this */
-let currentTest;
+let currentTest, focusEl = runBtn;
 beforeEach(async function() {
 	const fixture = new Promise(r => test.update = r);
 
@@ -163,6 +163,7 @@ function start() {
 }
 
 function run() {
+	focusEl = runBtn;
 	runBtn.disabled = true;
 	skipBtn.disabled = true;
 	test.run();
@@ -175,6 +176,7 @@ function runAll() {
 }
 
 function skip() {
+	focusEl = skipBtn;
 	run();
 	try {
 		currentTest.skip();