refactor: move View Stats and Sign In/Out buttons into DevButtons

Consolidates the dev-only stats and auth buttons into the DevButtons
component, passing user and onSignIn as props. Also comments out the
Twitter link in SocialLinks.

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

src/routes/+page.svelte

@@ -343,42 +343,6 @@
 		</div>
 		{#if isDev}
 			<div class="mt-8 flex flex-col items-stretch md:items-center gap-3">
-				<div class="flex flex-col md:flex-row gap-3">
-					<a
-						href="/stats?{user
-							? `userId=${user.id}`
-							: `anonymousId=${persistence.anonymousId}`}&tz={encodeURIComponent(
-							Intl.DateTimeFormat().resolvedOptions().timeZone,
-						)}"
-						class="inline-flex items-center justify-center px-4 py-2 bg-amber-600 text-white rounded-lg hover:bg-amber-700 transition-colors text-sm font-medium shadow-md"
-					>
-						📊 View Stats
-					</a>
-
-					{#if user}
-						<form
-							method="POST"
-							action="/auth/logout"
-							use:enhance
-							class="w-full md:w-auto"
-						>
-							<button
-								type="submit"
-								class="inline-flex items-center justify-center w-full px-4 py-2 bg-red-600 text-white rounded-lg hover:bg-red-700 transition-colors text-sm font-medium shadow-md"
-							>
-								🚪 Sign Out
-							</button>
-						</form>
-					{:else}
-						<button
-							onclick={() => (authModalOpen = true)}
-							class="inline-flex items-center justify-center px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors text-sm font-medium shadow-md"
-						>
-							🔐 Sign In
-						</button>
-					{/if}
-				</div>
-
 				<div
 					class="text-xs text-gray-600 dark:text-gray-300 bg-gray-100 dark:bg-gray-800 px-3 py-2 rounded border dark:border-gray-700"
 				>
@@ -412,7 +376,7 @@
 					<div>Daily Verse Date: {dailyVerse.date}</div>
 					<div>Streak: {streak}</div>
 				</div>
-				<DevButtons anonymousId={persistence.anonymousId} />
+				<DevButtons anonymousId={persistence.anonymousId} {user} onSignIn={() => (authModalOpen = true)} />
 			</div>
 		{/if}