feat: enforce custom Theme colors app-wide, add debug sample trips and poll

Replace all system colors (.secondary, Color(.secondarySystemBackground),
etc.) with Theme.textPrimary/textSecondary/textMuted/cardBackground/
surfaceGlow across 13 views. Remove PostHog debug logging. Add debug
settings for sample trips and hardcoded group poll preview.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SportsTime/Features/Polls/Views/PollCreationView.swift

@@ -46,6 +46,8 @@ struct PollCreationView: View {
                     }
                 }
             }
+            .scrollContentBackground(.hidden)
+            .themedBackground()
             .navigationTitle("Create Poll")
             .navigationBarTitleDisplayMode(.inline)
             .toolbar {
@@ -94,6 +96,7 @@ struct PollCreationView: View {
 // MARK: - Trip Selection Row
 
 private struct TripSelectionRow: View {
+    @Environment(\.colorScheme) private var colorScheme
     let trip: Trip
     let isSelected: Bool
     let onTap: () -> Void
@@ -104,18 +107,18 @@ private struct TripSelectionRow: View {
                 VStack(alignment: .leading, spacing: 4) {
                     Text(trip.displayName)
                         .font(.headline)
-                        .foregroundStyle(.primary)
+                        .foregroundStyle(Theme.textPrimary(colorScheme))
 
                     Text(tripSummary)
                         .font(.subheadline)
-                        .foregroundStyle(.secondary)
+                        .foregroundStyle(Theme.textSecondary(colorScheme))
                 }
 
                 Spacer()
 
                 Image(systemName: isSelected ? "checkmark.circle.fill" : "circle")
                     .font(.title2)
-                    .foregroundStyle(isSelected ? Theme.warmOrange : .secondary)
+                    .foregroundStyle(isSelected ? Theme.warmOrange : Theme.textMuted(colorScheme))
                     .accessibilityHidden(true)
             }
             .contentShape(Rectangle())