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/AppLaunchTests.swift

@@ -0,0 +1,52 @@
+//
+//  AppLaunchTests.swift
+//  Tests iOS
+//
+//  App launch and tab bar navigation tests.
+//
+
+import XCTest
+
+final class AppLaunchTests: BaseUITestCase {
+    override var seedFixture: String? { "empty" }
+
+    /// Verify the app launches to the Day tab and all 5 tabs are visible.
+    func testAppLaunches_TabBarVisible() {
+        let tabBar = TabBarScreen(app: app)
+        tabBar.assertTabBarVisible()
+
+        // All 5 tabs should exist
+        XCTAssertTrue(tabBar.dayTab.exists, "Day tab should exist")
+        XCTAssertTrue(tabBar.monthTab.exists, "Month tab should exist")
+        XCTAssertTrue(tabBar.yearTab.exists, "Year tab should exist")
+        XCTAssertTrue(tabBar.insightsTab.exists, "Insights tab should exist")
+        XCTAssertTrue(tabBar.settingsTab.exists, "Settings tab should exist")
+
+        captureScreenshot(name: "app_launched")
+    }
+
+    /// Navigate through every tab and verify each loads.
+    func testTabNavigation_AllTabsAccessible() {
+        let tabBar = TabBarScreen(app: app)
+
+        // Month tab
+        tabBar.tapMonth()
+        XCTAssertTrue(tabBar.monthTab.isSelected, "Month tab should be selected")
+
+        // Year tab
+        tabBar.tapYear()
+        XCTAssertTrue(tabBar.yearTab.isSelected, "Year tab should be selected")
+
+        // Insights tab
+        tabBar.tapInsights()
+        XCTAssertTrue(tabBar.insightsTab.isSelected, "Insights tab should be selected")
+
+        // Settings tab
+        tabBar.tapSettings()
+        XCTAssertTrue(tabBar.settingsTab.isSelected, "Settings tab should be selected")
+
+        // Back to Day
+        tabBar.tapDay()
+        XCTAssertTrue(tabBar.dayTab.isSelected, "Day tab should be selected")
+    }
+}