Major improvements: Firebase data migration, enhanced loading screens, multi-day prayer tracking

- Migrated all localStorage data to Firebase for cross-device sync
  - Prayer drafts now stored in users/{userId}/drafts
  - Reminder settings in users/{userId}/settings
  - Prayer statistics in users/{userId}/statistics
- Implemented persistent 'most prayed for' tracking in Firebase
- Enhanced loading screen with animated backgrounds and gradients
- Fixed auth session restoration on hard refresh
- Added prayedDates array for multi-day prayer tracking
- Calendar now accurately shows all days a prayer was prayed for
- Enabled Firestore offline persistence for offline-first experience
- Updated Firestore security rules for new data structure
- Improved clock display (removed leading zero from hours)
- Moved clock below date on homepage with appropriate sizing
- Fixed data loading race conditions between auth and Firestore

src/components/ThingsToPrayFor.tsx

@@ -13,6 +13,7 @@ interface Prayer {
   answerDetails?: string;
   prayFrequency?: number; // 1-7 times per week
   lastPrayedFor?: string; // ISO date string
+  prayedDates?: string[]; // Array of dates when prayed for
 }
 
 interface ThingsToPrayForProps {
@@ -85,7 +86,7 @@ export default function ThingsToPrayFor({ prayers, onEdit, onMarkPrayed }: Thing
                       (new Date().getTime() - new Date(prayer.date).getTime()) / (1000 * 60 * 60 * 24)
                     );
                     const today = new Date().toISOString().split('T')[0];
-                    const prayedToday = prayer.lastPrayedFor === today;
+                    const prayedToday = prayer.prayedDates?.includes(today) || prayer.lastPrayedFor === today;
                     
                     return (
                       <div