Improve UI consistency and add heart save button

- Add themed background to all tab views (Schedule, Settings, My Trips)
- Remove navigation titles from all screens (tab bar provides context)
- Add empty state to My Trips view
- Remove max driving hours slider from trip planner (available in Settings)
- Replace save menu with heart button overlay on trip detail map
- Add ability to unsave trips by tapping heart again

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

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

SportsTime/Features/Settings/Views/SettingsView.swift

@@ -29,7 +29,8 @@ struct SettingsView: View {
             // Reset
             resetSection
         }
-        .navigationTitle("Settings")
+        .scrollContentBackground(.hidden)
+        .themedBackground()
         .alert("Reset Settings", isPresented: $showResetConfirmation) {
             Button("Cancel", role: .cancel) { }
             Button("Reset", role: .destructive) {