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/manacore/apps/web/src/routes/(app)/+layout.svelte

@@ -25,7 +25,7 @@
 		{ href: '/dashboard', label: 'Dashboard', icon: 'home' },
 		{ href: '/organizations', label: 'Organizations', icon: 'building' },
 		{ href: '/teams', label: 'Teams', icon: 'users' },
-		{ href: '/subscription', label: 'Subscription', icon: 'creditCard' },
+		{ href: '/mana', label: 'Mana', icon: 'mana' },
 		{ href: '/settings', label: 'Settings', icon: 'settings' },
 	];