test: add initial test files and component stubs

src/containers/BerlinClock.tsx

@@ -0,0 +1,15 @@
+import { useState } from 'react';
+import { LampLine } from '../components/LampLine';
+import { useCurrentTime } from '../hooks/useCurrentTime';
+import { dateToBerlin } from '../utils';
+
+interface BerlinClockProps {
+  enabled: boolean;
+}
+
+export function BerlinClock({ enabled }: BerlinClockProps) {
+  const { currentTime } = useCurrentTime();
+  const berlin = dateToBerlin(currentTime);
+  // Will render four LampLine components
+  return null;
+}