Add debug bypass subscription toggle, tests, and data layer improvements

- Add runtime toggle in Settings (DEBUG only) to bypass subscription/hide trial banner
- IAPManager.bypassSubscription is now a @Published var persisted via UserDefaults
- Hide upgrade banner in SettingsTabView and trial warnings when bypass is enabled
- Add FeelsTests directory with integration tests
- Update DataController, DataControllerGET, DataControllerUPDATE
- Update Xcode project and scheme configuration
- Update localization strings and App Store screen docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/Persisence/DataController.swift

@@ -41,8 +41,8 @@ final class DataController: ObservableObject {
         return try? modelContext.fetch(descriptor).first
     }
 
-    private init() {
-        container = SharedModelContainer.createWithFallback(useCloudKit: true)
+    init(container: ModelContainer? = nil) {
+        self.container = container ?? SharedModelContainer.createWithFallback(useCloudKit: true)
     }