feat(polls): implement group trip polling MVP

Add complete group trip polling feature allowing users to share trips
with friends for voting using Borda count scoring.

New components:
- TripPoll and PollVote domain models with share codes and rankings
- LocalTripPoll and LocalPollVote SwiftData models for persistence
- CKTripPoll and CKPollVote CloudKit record wrappers
- PollService actor for CloudKit CRUD operations and subscriptions
- PollCreation/Detail/Voting views and view models
- Deep link handling for sportstime://poll/{code} URLs
- Debug Pro status override toggle in Settings

Integration:
- HomeView shows polls section in My Trips
- SportsTimeApp registers SwiftData models and handles deep links

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

SportsTime/Features/Polls/Views/PollsListView.swift

@@ -0,0 +1,152 @@
+//
+//  PollsListView.swift
+//  SportsTime
+//
+//  View for listing user's polls
+//
+
+import SwiftUI
+
+struct PollsListView: View {
+    @Environment(\.colorScheme) private var colorScheme
+    @State private var polls: [TripPoll] = []
+    @State private var isLoading = false
+    @State private var error: PollError?
+    @State private var showJoinPoll = false
+    @State private var joinCode = ""
+
+    var body: some View {
+        Group {
+            if isLoading && polls.isEmpty {
+                ProgressView("Loading polls...")
+            } else if polls.isEmpty {
+                emptyState
+            } else {
+                pollsList
+            }
+        }
+        .navigationTitle("Group Polls")
+        .toolbar {
+            ToolbarItem(placement: .primaryAction) {
+                Button {
+                    showJoinPoll = true
+                } label: {
+                    Image(systemName: "link.badge.plus")
+                }
+            }
+        }
+        .refreshable {
+            await loadPolls()
+        }
+        .task {
+            await loadPolls()
+        }
+        .alert("Join Poll", isPresented: $showJoinPoll) {
+            TextField("Enter code", text: $joinCode)
+                .textInputAutocapitalization(.characters)
+            Button("Join") {
+                // Navigation will be handled by deep link
+                if !joinCode.isEmpty {
+                    // TODO: Navigate to poll detail
+                }
+            }
+            Button("Cancel", role: .cancel) {
+                joinCode = ""
+            }
+        } message: {
+            Text("Enter the 6-character poll code")
+        }
+        .alert("Error", isPresented: .constant(error != nil)) {
+            Button("OK") {
+                error = nil
+            }
+        } message: {
+            if let error {
+                Text(error.localizedDescription)
+            }
+        }
+    }
+
+    @ViewBuilder
+    private var emptyState: some View {
+        ContentUnavailableView {
+            Label("No Polls", systemImage: "chart.bar.doc.horizontal")
+        } description: {
+            Text("Create a poll from your saved trips to let friends vote on which trip to take.")
+        }
+    }
+
+    @ViewBuilder
+    private var pollsList: some View {
+        List {
+            ForEach(polls) { poll in
+                NavigationLink(value: poll) {
+                    PollRowView(poll: poll)
+                }
+            }
+        }
+        .listStyle(.plain)
+        .navigationDestination(for: TripPoll.self) { poll in
+            PollDetailView(pollId: poll.id)
+        }
+    }
+
+    private func loadPolls() async {
+        isLoading = true
+        error = nil
+
+        do {
+            polls = try await PollService.shared.fetchMyPolls()
+        } catch let pollError as PollError {
+            error = pollError
+        } catch {
+            self.error = .unknown(error)
+        }
+
+        isLoading = false
+    }
+}
+
+// MARK: - Poll Row View
+
+private struct PollRowView: View {
+    @Environment(\.colorScheme) private var colorScheme
+    let poll: TripPoll
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            HStack {
+                Text(poll.title)
+                    .font(.headline)
+
+                Spacer()
+
+                Text(poll.shareCode)
+                    .font(.caption)
+                    .fontWeight(.semibold)
+                    .foregroundStyle(Theme.warmOrange)
+                    .padding(.horizontal, 8)
+                    .padding(.vertical, 4)
+                    .background(Theme.warmOrange.opacity(0.15))
+                    .clipShape(Capsule())
+            }
+
+            HStack {
+                Label("\(poll.tripSnapshots.count) trips", systemImage: "map")
+
+                Spacer()
+
+                Text(poll.createdAt, style: .date)
+            }
+            .font(.caption)
+            .foregroundStyle(.secondary)
+        }
+        .padding(.vertical, 4)
+    }
+}
+
+#Preview {
+    NavigationStack {
+        PollsListView()
+    }
+}