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>

Feels.xcodeproj/xcshareddata/xcschemes/Feels (iOS).xcscheme

@@ -32,9 +32,9 @@
             skipped = "NO">
             <BuildableReference
                BuildableIdentifier = "primary"
-               BlueprintIdentifier = "1CD90B01278C7DE0001C4FEA"
-               BuildableName = "Tests iOS.xctest"
-               BlueprintName = "Tests iOS"
+               BlueprintIdentifier = "B375A511826E3AB53E2CF51A"
+               BuildableName = "FeelsTests.xctest"
+               BlueprintName = "FeelsTests"
                ReferencedContainer = "container:Feels.xcodeproj">
             </BuildableReference>
          </TestableReference>