refactor: rename ManaDeck to Cards across entire monorepo

Rename the flashcard/deck management app from ManaDeck to Cards:
- Directory: apps/manadeck → apps/cards, packages/manadeck-database → packages/cards-database
- Packages: @manadeck/* → @cards/*, @manacore/manadeck-database → @manacore/cards-database
- Domain: manadeck.mana.how → cards.mana.how
- Storage: manadeck-storage → cards-storage
- Database: manadeck → cards
- All shared packages, infra configs, services, i18n, and docs updated
- 244 files changed, zero remaining manadeck references

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

packages/shared-utils/src/analytics.ts

@@ -245,9 +245,9 @@ export const ContactsEvents = {
 };
 
 /**
- * ManaDeck App Events
+ * Cards App Events
  */
-export const ManaDeckEvents = {
+export const CardsEvents = {
 	deckCreated: () => trackEvent('deck_created'),
 	deckDeleted: () => trackEvent('deck_deleted'),
 	deckStudied: (cardsCount: number) => trackEvent('deck_studied', { cards: cardsCount }),