fix(wizard): enable Plan My Trip button with default values

- Add debug toggle in Settings to override Pro subscription status (DEBUG builds only, defaults to true)
- Auto-validate wizard step flags on appear so button enables without explicit user interaction:
  - DatesStep: calls updateHasSetDates() on appear
  - RoutePreferenceStep: sets hasSetRoutePreference on appear
  - RepeatCitiesStep: sets hasSetRepeatCities on appear

Previously, canPlanTrip required all flags to be explicitly set by user interaction, even when valid defaults were showing.

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

SportsTime/Features/Trip/Views/Wizard/Steps/DatesStep.swift

@@ -43,6 +43,10 @@ struct DatesStep: View {
             RoundedRectangle(cornerRadius: Theme.CornerRadius.large)
                 .stroke(Theme.surfaceGlow(colorScheme), lineWidth: 1)
         }
+        .onAppear {
+            // Auto-validate if dates are already valid (e.g., defaults)
+            updateHasSetDates()
+        }
     }
 
     private func updateHasSetDates() {