Review prompt tras check-in: ≥2 meses de histórico, una vez por versión (build 85) #41

- ReviewRequestService: gate por meses distintos con snapshots + versión
- QuickUpdateView.saveAll y AddSnapshotView.performSave (solo alta, no edición) piden reseña via \.requestReview tras cerrar el sheet
- Motivo: 0 ratings visibles en US, 1 en ES — la ficha no convierte

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VXtwQP6nYnbLFVqsHiTK5G

PortfolioJournal/Utilities/ReviewRequestService.swift

@@ -0,0 +1,38 @@
+import Foundation
+import CoreData
+
+/// Decides when to ask for an App Store rating: after a "positive moment"
+/// (a saved check-in), only once the habit is established (≥2 distinct months
+/// of snapshots) and at most once per app version. Apple additionally caps
+/// the system prompt at 3 displays per year, so over-calling is safe.
+///
+/// Call sites own the actual prompt via SwiftUI's `\.requestReview` — this
+/// service only answers "should we ask now?" and records that we did.
+@MainActor
+enum ReviewRequestService {
+    private static let lastVersionKey = "reviewRequest.lastVersion"
+
+    /// Returns true at most once per app version, and only when the user has
+    /// snapshots in 2+ distinct months (they've seen the app deliver value).
+    /// Marks the version as asked when returning true.
+    static func shouldRequestAfterCheckIn() -> Bool {
+        guard distinctSnapshotMonths() >= 2 else { return false }
+
+        let version = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "unknown"
+        let defaults = UserDefaults.standard
+        guard defaults.string(forKey: lastVersionKey) != version else { return false }
+
+        defaults.set(version, forKey: lastVersionKey)
+        return true
+    }
+
+    private static func distinctSnapshotMonths() -> Int {
+        let request = NSFetchRequest<Snapshot>(entityName: "Snapshot")
+        guard let snapshots = try? CoreDataStack.shared.viewContext.fetch(request) else { return 0 }
+        let calendar = Calendar.current
+        let months = Set(snapshots.map { snapshot in
+            calendar.dateComponents([.year, .month], from: snapshot.date)
+        })
+        return months.count
+    }
+}