Workouts 2.0: re-base persistence on iCloud Drive documents

Replace Core Data + NSPersistentCloudKitContainer + App-Group store +
WatchConnectivity dictionary sync with the QuickRabbit iCloud-documents
architecture:

- iCloud Drive JSON documents are the sole source of truth (one file per
  aggregate: Splits/<ULID>.json, Workouts/YYYY/MM/<ULID>.json), with a
  rebuildable SwiftData cache populated only by an NSMetadataQuery observer
  and a connect-time reconcile. Soft-delete tombstones; hard iCloud gate.
- Shared model layer (ULID, Codable *Documents + stateless mappers, @Model
  cache entities, SwiftData container) compiled into both targets.
- New iPhone<->Watch bridge over WatchConnectivity keyed by ULIDs; the phone
  is the sole writer of iCloud Drive, the watch round-trips documents.
- AppServices DI + iCloud-required root gate; Swift 6 strict concurrency.
- Starter splits generated on demand from the bundled YAML catalogs.
- Migrate to XcodeGen (project.yml), iOS 26 / watchOS 26; CloudDocuments
  entitlement (drop CloudKit/App Group/aps-environment).
- Duration stored as Int seconds (was a Date epoch hack); fix workout
  end-on-create, undismissable delete dialog, toolbar-hiding nav stacks,
  and the Settings placeholder.
- Add README/CHANGELOG/LICENSE, .gitignore, refreshed REQUIREMENTS, and the
  Scripts/ TestFlight pipeline (release.sh + ASC API scripts).

MARKETING_VERSION 2.0.

Workouts/Views/Splits/SplitListView.swift

@@ -8,64 +8,44 @@
 //
 
 import SwiftUI
-import CoreData
+import SwiftData
 
 struct SplitListView: View {
-    @Environment(\.managedObjectContext) private var viewContext
+    @Environment(SyncEngine.self) private var sync
+    @Environment(\.modelContext) private var modelContext
 
-    @FetchRequest(
-        sortDescriptors: [
-            NSSortDescriptor(keyPath: \Split.order, ascending: true),
-            NSSortDescriptor(keyPath: \Split.name, ascending: true)
-        ],
-        animation: .default
-    )
-    private var fetchedSplits: FetchedResults<Split>
-
-    @State private var splits: [Split] = []
-    @State private var allowSorting: Bool = true
+    @Query(sort: \Split.order) private var splits: [Split]
 
     var body: some View {
         ScrollView {
             LazyVGrid(columns: [GridItem(.flexible()), GridItem(.flexible())], spacing: 16) {
-                SortableForEach($splits, allowReordering: $allowSorting) { split, dragging in
+                ForEach(splits) { split in
                     NavigationLink {
                         SplitDetailView(split: split)
                     } label: {
                         SplitItem(split: split)
-                            .overlay(dragging ? Color.white.opacity(0.8) : Color.clear)
                     }
                 }
             }
             .padding()
         }
         .overlay {
-            if fetchedSplits.isEmpty {
+            if splits.isEmpty {
                 ContentUnavailableView(
-                    "No Splits Yet",
-                    systemImage: "dumbbell.fill",
-                    description: Text("Create a split to organize your workout routine.")
+                    label: {
+                        Label("No Splits Yet", systemImage: "dumbbell.fill")
+                    },
+                    description: {
+                        Text("Create a split to organize your workout routine.")
+                    },
+                    actions: {
+                        Button("Add Starter Splits") {
+                            Task { await SplitSeeder.seedDefaults(into: modelContext, using: sync) }
+                        }
+                        .buttonStyle(.borderedProminent)
+                    }
                 )
             }
         }
-        .onAppear {
-            splits = Array(fetchedSplits)
-        }
-        .onChange(of: fetchedSplits.count) { _, _ in
-            splits = Array(fetchedSplits)
-        }
-        .onChange(of: splits) { _, _ in
-            saveContext()
-        }
-    }
-
-    private func saveContext() {
-        if viewContext.hasChanges {
-            do {
-                try viewContext.save()
-            } catch {
-                print("Error saving after reorder: \(error)")
-            }
-        }
     }
 }