fix: replace all manacore.app URLs with mana.how

The production domain is mana.how, not manacore.app. Updated all
references across shared-branding APP_URLS, app configs, landing pages,
docs, help content, calendar iCal UIDs, and deploy scripts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/nutriphi/apps/landing/astro.config.mjs

@@ -3,5 +3,5 @@ import tailwind from '@astrojs/tailwind';
 
 export default defineConfig({
 	integrations: [tailwind()],
-	site: 'https://nutriphi.manacore.app',
+	site: 'https://nutriphi.mana.how',
 });

apps/nutriphi/apps/landing/src/pages/index.astro

@@ -100,7 +100,7 @@ const faqs = [
 					<span class="font-semibold text-white">NutriPhi</span>
 				</div>
 				<a
-					href="https://app.nutriphi.manacore.app"
+					href="https://nutriphi.mana.how"
 					class="px-4 py-2 bg-primary hover:bg-primary-hover text-white font-medium rounded-lg transition-colors"
 				>
 					Jetzt starten
@@ -144,7 +144,7 @@ const faqs = [
 
 				<div class="flex flex-col sm:flex-row gap-4 justify-center">
 					<a
-						href="https://app.nutriphi.manacore.app"
+						href="https://nutriphi.mana.how"
 						class="px-8 py-4 bg-primary hover:bg-primary-hover text-white font-semibold rounded-xl transition-colors text-lg"
 					>
 						Kostenlos starten
@@ -240,7 +240,7 @@ const faqs = [
 					Kostenlos. Ohne Kreditkarte. Sofort loslegen.
 				</p>
 				<a
-					href="https://app.nutriphi.manacore.app"
+					href="https://nutriphi.mana.how"
 					class="inline-block px-10 py-4 bg-primary hover:bg-primary-hover text-white font-semibold rounded-xl transition-colors text-lg"
 				>
 					Jetzt kostenlos registrieren