Project 1 – Part 3: Event fetching, caching & creation flow

[adilkabbariBVC]

This PR implements Part 3 requirements:

• Fetch events from /events on map init; cache to AsyncStorage; fall back to cache when offline
• Show only future events as map markers; update bottom label to total count
• “+” button starts event creation flow (CreateEvent screen)
• CreateEvent form with required fields & validation (Save disabled until valid)
• Camera/library permissions checks for image; upload to ImgBB; include image URL; show thumbnail & file details
• Persist new event via POST /events; after Next, navigate back to map and refetch to include the new event
• Minor UI fixes for React Native & Expo compatibility
• Tested successfully with local json-server-auth instance at http://192.168.1.105:3333