Add EV charging discovery feature (disabled by flag)

- Create EVChargingService using MapKit POI search for EV chargers
- Add ItineraryBuilder.enrichWithEVChargers() for post-planning enrichment
- Update TravelSection in TripDetailView with expandable charger list
- Add FeatureFlags.enableEVCharging toggle (default: false)
- Include EVChargingFeature.md documenting API overhead

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

SportsTime/Features/Trip/Views/TripCreationView.swift

@@ -535,12 +535,14 @@ struct TripCreationView: View {
                 Divider()
                     .overlay(Theme.surfaceGlow(colorScheme))
 
-                // EV Charging
-                ThemedToggle(
-                    label: "EV Charging Needed",
-                    isOn: $viewModel.needsEVCharging,
-                    icon: "bolt.car"
-                )
+                // EV Charging (feature flagged)
+                if FeatureFlags.enableEVCharging {
+                    ThemedToggle(
+                        label: "EV Charging Needed",
+                        isOn: $viewModel.needsEVCharging,
+                        icon: "bolt.car"
+                    )
+                }
 
                 // Drivers
                 ThemedStepper(