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/ViewModels/PollDetailViewModel.swift

@@ -0,0 +1,144 @@
+//
+//  PollDetailViewModel.swift
+//  SportsTime
+//
+//  ViewModel for viewing poll details and results
+//
+
+import Foundation
+import SwiftUI
+
+@Observable
+@MainActor
+final class PollDetailViewModel {
+    var poll: TripPoll?
+    var votes: [PollVote] = []
+    var myVote: PollVote?
+    var isLoading = false
+    var isRefreshing = false
+    var error: PollError?
+
+    private let pollService = PollService.shared
+
+    var results: PollResults? {
+        guard let poll else { return nil }
+        return PollResults(poll: poll, votes: votes)
+    }
+
+    var isOwner: Bool {
+        get async {
+            guard let poll else { return false }
+            do {
+                let userId = try await pollService.getCurrentUserRecordID()
+                return poll.ownerId == userId
+            } catch {
+                return false
+            }
+        }
+    }
+
+    var hasVoted: Bool {
+        myVote != nil
+    }
+
+    var shareURL: URL? {
+        poll?.shareURL
+    }
+
+    func loadPoll(byId pollId: UUID) async {
+        isLoading = true
+        error = nil
+
+        do {
+            async let pollTask = pollService.fetchPoll(byId: pollId)
+            async let votesTask = pollService.fetchVotes(forPollId: pollId)
+            async let myVoteTask = pollService.fetchMyVote(forPollId: pollId)
+
+            let (fetchedPoll, fetchedVotes, fetchedMyVote) = try await (pollTask, votesTask, myVoteTask)
+
+            self.poll = fetchedPoll
+            self.votes = fetchedVotes
+            self.myVote = fetchedMyVote
+
+            // Subscribe to vote updates
+            try? await pollService.subscribeToVoteUpdates(forPollId: pollId)
+        } catch let pollError as PollError {
+            error = pollError
+        } catch {
+            self.error = .unknown(error)
+        }
+
+        isLoading = false
+    }
+
+    func loadPoll(byShareCode shareCode: String) async {
+        isLoading = true
+        error = nil
+
+        do {
+            let fetchedPoll = try await pollService.fetchPoll(byShareCode: shareCode)
+            self.poll = fetchedPoll
+
+            // Now fetch votes with the poll ID
+            async let votesTask = pollService.fetchVotes(forPollId: fetchedPoll.id)
+            async let myVoteTask = pollService.fetchMyVote(forPollId: fetchedPoll.id)
+
+            let (fetchedVotes, fetchedMyVote) = try await (votesTask, myVoteTask)
+            self.votes = fetchedVotes
+            self.myVote = fetchedMyVote
+
+            // Subscribe to vote updates
+            try? await pollService.subscribeToVoteUpdates(forPollId: fetchedPoll.id)
+        } catch let pollError as PollError {
+            error = pollError
+        } catch {
+            self.error = .unknown(error)
+        }
+
+        isLoading = false
+    }
+
+    func refresh() async {
+        guard let poll else { return }
+
+        isRefreshing = true
+
+        do {
+            async let votesTask = pollService.fetchVotes(forPollId: poll.id)
+            async let myVoteTask = pollService.fetchMyVote(forPollId: poll.id)
+
+            let (fetchedVotes, fetchedMyVote) = try await (votesTask, myVoteTask)
+            self.votes = fetchedVotes
+            self.myVote = fetchedMyVote
+        } catch {
+            // Silently fail refresh - user can pull to refresh again
+        }
+
+        isRefreshing = false
+    }
+
+    func deletePoll() async -> Bool {
+        guard let poll else { return false }
+
+        isLoading = true
+        error = nil
+
+        do {
+            try await pollService.deletePoll(poll.id)
+            try? await pollService.unsubscribeFromVoteUpdates()
+            self.poll = nil
+            return true
+        } catch let pollError as PollError {
+            error = pollError
+        } catch {
+            self.error = .unknown(error)
+        }
+
+        isLoading = false
+        return false
+    }
+
+    func cleanup() async {
+        try? await pollService.unsubscribeFromVoteUpdates()
+    }
+}