Add XCUITest suite with 27 test files covering unmapped P1 test cases

- Add 8 new test files: HeaderMoodLogging (TC-002), DayViewGrouping (TC-019),
  AllDayViewStyles (TC-021), MonthViewInteraction (TC-030), PaywallGate
  (TC-032/039/048), AppTheme (TC-070), IconPack (TC-072),
  PremiumCustomization (TC-075)
- Add accessibility IDs for paywall overlays, icon packs, app theme cards,
  and day view section headers
- Add --expire-trial launch argument to UITestMode for paywall gate testing
- Update QA test plan spreadsheet with XCUITest names for 14 test cases
- Include existing test infrastructure: screen objects, helpers, base class,
  and 19 previously written test files

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

Shared/Views/SettingsView/SettingsView.swift

@@ -827,6 +827,7 @@ struct SettingsContentView: View {
                 .padding()
             }
         }
+        .accessibilityIdentifier(AccessibilityID.Settings.clearDataButton)
         .fixedSize(horizontal: false, vertical: true)
         .cornerRadius(Constants.viewsCornerRaidus, corners: [.topLeft, .topRight, .bottomLeft, .bottomRight])
     }
@@ -1073,6 +1074,7 @@ struct SettingsContentView: View {
                     .foregroundColor(textColor)
             })
             .accessibilityHint(String(localized: "View the app introduction again"))
+            .accessibilityIdentifier(AccessibilityID.Settings.showOnboardingButton)
             .padding()
         }
         .fixedSize(horizontal: false, vertical: true)
@@ -1168,6 +1170,7 @@ struct SettingsContentView: View {
                     }
                 ))
                 .labelsHidden()
+                .accessibilityIdentifier(AccessibilityID.Settings.analyticsToggle)
                 .accessibilityLabel("Share Analytics")
                 .accessibilityHint("Toggle anonymous usage analytics")
             }
@@ -1903,6 +1906,7 @@ struct SettingsView: View {
                     }
                 ))
                 .labelsHidden()
+                .accessibilityIdentifier(AccessibilityID.Settings.analyticsToggle)
                 .accessibilityLabel("Share Analytics")
                 .accessibilityHint("Toggle anonymous usage analytics")
             }