feat(v3​.1​.0): add ​Store​Kit integration and ​Pro tier

• implement Purchase​Service using StoreKit 2
• activate feature tiers based on entitlement
• add minimal paywall and restore flow
• enforce free-tier limits with upgrade paths
• integrate Pro status into settings
• ensure clean and non-intrusive monetization flow

1 files changed, 25 insertions, 0 deletions

diff --git a/DomainDig/RootTabView.swift b/DomainDig/RootTabView.swift
index 19ea444..2d2b8ed 100644
--- a/DomainDig/RootTabView.swift
+++ b/DomainDig/RootTabView.swift
@@ -2,8 +2,11 @@ import SwiftUI
 
 struct RootTabView: View {
     @Bindable var viewModel: DomainViewModel
+    @State private var purchaseService = PurchaseService.shared
 
     var body: some View {
+        let _ = purchaseService.currentTier
+
         TabView {
             ContentView(viewModel: viewModel)
                 .tabItem {
@@ -38,5 +41,27 @@ struct RootTabView: View {
                 Label("Settings", systemImage: "gearshape")
             }
         }
+        .sheet(isPresented: Binding(
+            get: { viewModel.isPaywallPresented },
+            set: { viewModel.isPaywallPresented = $0 }
+        )) {
+            PaywallView()
+        }
+        .alert(item: Binding(
+            get: { viewModel.upgradePrompt },
+            set: { viewModel.upgradePrompt = $0 }
+        )) { prompt in
+            Alert(
+                title: Text(prompt.title),
+                message: Text(prompt.message),
+                primaryButton: .default(Text("Open Paywall")) {
+                    viewModel.upgradePrompt = nil
+                    viewModel.isPaywallPresented = true
+                },
+                secondaryButton: .cancel(Text("Continue")) {
+                    viewModel.upgradePrompt = nil
+                }
+            )
+        }
     }
 }