feat: add progress page with activity calendar, book grid, and insights

Adds a new /progress route showing a personalized Bible knowledge dashboard
with stat cards, book mastery grid, 30-day activity calendar, skill growth
chart, streak milestones, and section insights. Links added from WinScreen
(logged-in users) and DevButtons.

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

src/lib/components/WinScreen.svelte

@@ -329,7 +329,14 @@
 		</div>
 	{/if}
 
-	{#if !isLoggedIn}
+	{#if isLoggedIn}
+		<a
+			href="/progress"
+			class="text-sm text-center text-gray-500 dark:text-gray-400 hover:text-emerald-600 dark:hover:text-emerald-400 transition-colors"
+		>
+			View your progress →
+		</a>
+	{:else}
 		<div class="signin-prompt">
 			<p class="signin-text">
 				Sign in to save your streak &amp; track your progress