feat: ask which games you play on first run

A calendar full of games you don't play is worse than an empty one — it
buries the thing you came for.

Nothing is preselected; the button stays disabled until a game is picked,
which is clearer than guessing and hoping the reader notices. The choice is
stored as hiddenGames, the inverse, so a game added later shows up by
default rather than staying invisible.

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

src/client/App.tsx

@@ -5,6 +5,7 @@ import { EventDetail } from "./components/EventDetail.tsx";
 import { EventRow, type RowEvent } from "./components/EventRow.tsx";
 import { NextUp } from "./components/NextUp.tsx";
 import { Timeline } from "./components/Timeline.tsx";
+import { Welcome } from "./components/Welcome.tsx";
 import { useCompletions } from "./state/useCompletions.ts";
 import { usePrefs } from "./state/usePrefs.ts";
 import { clockFor, DAY, endingSoonestFirst, formatRemaining } from "../shared/time.ts";
@@ -91,6 +92,25 @@ export function App() {
     );
   }
 
+  // First run: ask which games before showing a calendar full of ones they
+  // don't play. Stored as hiddenGames (the inverse) so a game added later shows
+  // up by default rather than staying invisible.
+  if (!prefs.onboarded) {
+    return (
+      <Shell>
+        <Welcome
+          available={games}
+          onConfirm={(chosen) =>
+            update({
+              onboarded: true,
+              hiddenGames: games.filter((g) => !chosen.includes(g)),
+            })
+          }
+        />
+      </Shell>
+    );
+  }
+
   const staleSources = state.feed.sources.filter(
     (s) => s.lastSuccessAt === null || now - Date.parse(s.lastSuccessAt) > 2 * DAY,
   );