feat: add the Event Clock interface

Opens on the single event closest to expiring, at a size nothing else
competes with — the reader arrives with one question. Below it, live events
ordered by what ends soonest, then a quiet timeline view with one lane per
game.

Countdowns use tabular figures so ticking never reflows the row.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

src/client/main.tsx

@@ -0,0 +1,12 @@
+import { StrictMode } from "react";
+import { createRoot } from "react-dom/client";
+import { App } from "./App.tsx";
+
+const root = document.getElementById("root");
+if (root === null) throw new Error("#root is missing from index.html");
+
+createRoot(root).render(
+  <StrictMode>
+    <App />
+  </StrictMode>,
+);