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>

Tests iOS/SettingsTests.swift

@@ -0,0 +1,44 @@
+//
+//  SettingsTests.swift
+//  Tests iOS
+//
+//  Settings tab structure and segmented control tests.
+//
+
+import XCTest
+
+final class SettingsTests: BaseUITestCase {
+    override var seedFixture: String? { "empty" }
+    override var bypassSubscription: Bool { false }
+
+    /// Navigate to Settings and verify the header and upgrade banner appear.
+    func testSettingsTab_ShowsHeaderAndUpgradeBanner() {
+        let tabBar = TabBarScreen(app: app)
+        let settingsScreen = tabBar.tapSettings()
+
+        settingsScreen.assertVisible()
+
+        // With subscription NOT bypassed, upgrade banner should be visible
+        settingsScreen.assertUpgradeBannerVisible()
+
+        captureScreenshot(name: "settings_with_upgrade_banner")
+    }
+
+    /// Toggle between Customize and Settings segments.
+    func testSettingsTab_SegmentedControlToggle() {
+        let tabBar = TabBarScreen(app: app)
+        let settingsScreen = tabBar.tapSettings()
+
+        settingsScreen.assertVisible()
+
+        // Switch to Settings sub-tab
+        settingsScreen.tapSettingsTab()
+        // Verify we're on the Settings sub-tab (check for a settings-specific element)
+        // The "Settings" segment should be selected now
+        captureScreenshot(name: "settings_subtab")
+
+        // Switch back to Customize
+        settingsScreen.tapCustomizeTab()
+        captureScreenshot(name: "customize_subtab")
+    }
+}