Add Rybbit analytics alongside Umami

- Load Rybbit script via app.html (recommended SvelteKit approach)
- Mirror all Umami custom events (First guess, Guessed correctly, Share, Copy to Clipboard, social link clicks) with rybbit.event()
- Identify logged-in users with name/email traits; anonymous users by stable UUID

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/stores/game-persistence.svelte.ts

@@ -17,11 +17,18 @@ function getOrCreateAnonymousId(): string {
 // Reactive store that keeps in-memory game state in sync with localStorage.
 // Accepts getter functions (rather than plain values) so Svelte's reactivity
 // system can track dependencies and re-run effects when they change.
+type AuthUser = {
+	id: string;
+	firstName?: string | null;
+	lastName?: string | null;
+	email?: string | null;
+};
+
 export function createGamePersistence(
 	getDate: () => string,
 	getReference: () => string,
 	getCorrectBookId: () => string,
-	getUserId: () => string | undefined,
+	getUser: () => AuthUser | null | undefined,
 ) {
 	let guesses = $state<Guess[]>([]);
 	let anonymousId = $state("");
@@ -34,18 +41,27 @@ export function createGamePersistence(
 	$effect(() => {
 		if (!browser) return;
 
-		const userId = getUserId();
+		const user = getUser();
 		// CRITICAL: If user is logged in, ALWAYS use their user ID
-		if (userId) {
-			anonymousId = userId;
+		if (user) {
+			anonymousId = user.id;
 		} else {
 			anonymousId = getOrCreateAnonymousId();
 		}
 
-		// Tell Umami analytics which player this is so events are grouped correctly.
+		// Tell analytics which player this is so events are grouped correctly.
 		if ((window as any).umami) {
 			(window as any).umami.identify(anonymousId);
 		}
+		if (user) {
+			const nameParts = [user.firstName, user.lastName].filter(Boolean);
+			(window as any).rybbit?.identify(user.id, {
+				...(nameParts.length ? { name: nameParts.join(' ') } : {}),
+				...(user.email ? { email: user.email } : {}),
+			});
+		} else {
+			(window as any).rybbit?.identify(anonymousId);
+		}
 
 		const date = getDate();
 		const reference = getReference();