feat: rename subscription routes to /mana across all apps

- Add /mana route to chat web app with SubscriptionPage
- Add manaHref prop to PillNavigation for user dropdown link
- Add mana icon to PillDropdown component
- Rename /subscription to /mana in picture, manacore, and manadeck apps
- Update navigation items to use mana icon and label

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/chat/apps/web/src/routes/(protected)/+layout.svelte

@@ -187,6 +187,7 @@
 			{appItems}
 			{userEmail}
 			settingsHref="/settings"
+			manaHref="/mana"
 		/>
 
 		<!-- Main Content with dynamic padding based on nav mode -->

apps/chat/apps/web/src/routes/(protected)/mana/+page.svelte

@@ -0,0 +1,32 @@
+<script lang="ts">
+	import { SubscriptionPage } from '@manacore/shared-subscription-ui';
+
+	function handleSubscribe(planId: string) {
+		console.log('Subscribe to plan:', planId);
+		alert(`Abo "${planId}" ausgewählt. Bezahlsystem wird noch integriert.`);
+	}
+
+	function handleBuyPackage(packageId: string) {
+		console.log('Buy package:', packageId);
+		alert(`Paket "${packageId}" ausgewählt. Bezahlsystem wird noch integriert.`);
+	}
+</script>
+
+<svelte:head>
+	<title>Mana - ManaChat</title>
+</svelte:head>
+
+<div class="min-h-screen p-4 md:p-8" style="background-color: hsl(var(--color-background));">
+	<div class="mx-auto max-w-6xl">
+		<SubscriptionPage
+			appName="ManaChat"
+			onSubscribe={handleSubscribe}
+			onBuyPackage={handleBuyPackage}
+			currentPlanId="free"
+			pageTitle="Wähle dein Abo"
+			subscriptionsTitle="Abonnements"
+			packagesTitle="Einmal-Pakete"
+			yearlyDiscount="2 Monate gratis"
+		/>
+	</div>
+</div>