VSN-2100/ feat(trip tracking) : add real-time passenger trip tracking with HTTP polling

The changes included in this MR are as follows :

• Implement real-time driver position tracking using HTTP polling (every 3s)
• Fix multiple navigation and state management bugs in the tracking screen

Updated: Tracking store (trackingStore.ts)

• Connect/disconnect polling actions integrated into Zustand store
• Dedicated validatePassengerTrip() function for API data validation (id, date format, status)
• 5-minute cache on fetchTrips to avoid redundant API calls on tab switches

Fixed: Tracking screen

• Stale tripId from Expo Router: only use tripId param when fromPlanning === "true"
• Trip selection: sort by closest to current time instead of returning first match
• Back button: useEffect deps changed from [] to [fromPlanning] so it reacts to navigation changes
• Always disconnect polling in cleanup, removed !isTrackingActive guard