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/PollDetailView.swift

@@ -452,7 +452,7 @@ private struct TripPreviewCard: View {
 
                     Text(trip.displayName)
                         .font(.headline)
-                        .foregroundStyle(.primary)
+                        .foregroundStyle(Theme.textPrimary(colorScheme))
                 }
 
                 // Date range and duration
@@ -462,7 +462,7 @@ private struct TripPreviewCard: View {
                     Label("\(trip.tripDuration) days", systemImage: "clock")
                 }
                 .font(.caption)
-                .foregroundStyle(.secondary)
+                .foregroundStyle(Theme.textSecondary(colorScheme))
 
                 HStack {
                     Label("\(trip.stops.count) stops", systemImage: "mappin.and.ellipse")
@@ -470,13 +470,13 @@ private struct TripPreviewCard: View {
                     Label("\(trip.stops.flatMap { $0.games }.count) games", systemImage: "sportscourt")
                 }
                 .font(.caption)
-                .foregroundStyle(.secondary)
+                .foregroundStyle(Theme.textSecondary(colorScheme))
             }
 
             Image(systemName: "chevron.right")
                 .font(.caption)
                 .fontWeight(.semibold)
-                .foregroundStyle(.tertiary)
+                .foregroundStyle(Theme.textMuted(colorScheme))
                 .accessibilityHidden(true)
         }
         .padding()
@@ -484,7 +484,7 @@ private struct TripPreviewCard: View {
         .clipShape(RoundedRectangle(cornerRadius: 12))
         .overlay(
             RoundedRectangle(cornerRadius: 12)
-                .strokeBorder(Color.secondary.opacity(0.1), lineWidth: 1)
+                .strokeBorder(Theme.surfaceGlow(colorScheme), lineWidth: 1)
         )
     }
 }