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/CustomizationTests.swift

@@ -0,0 +1,105 @@
+//
+//  CustomizationTests.swift
+//  Tests iOS
+//
+//  Customization tests: theme modes, voting layouts, day view styles.
+//
+
+import XCTest
+
+final class CustomizationTests: BaseUITestCase {
+    override var seedFixture: String? { "single_mood" }
+    override var bypassSubscription: Bool { true }
+
+    /// TC-071: Switch between all 4 theme modes without crashing.
+    func testThemeModes_AllSelectable() {
+        let tabBar = TabBarScreen(app: app)
+        let settingsScreen = tabBar.tapSettings()
+        settingsScreen.assertVisible()
+
+        // Should already be on Customize sub-tab
+        // Theme buttons are: System, iFeel, Dark, Light
+        let themeNames = ["System", "iFeel", "Dark", "Light"]
+
+        for themeName in themeNames {
+            let button = app.buttons["customize_theme_\(themeName.lowercased())"]
+            if button.waitForExistence(timeout: 3) {
+                button.tap()
+                // Brief pause for theme to apply
+            }
+        }
+
+        captureScreenshot(name: "theme_modes_cycled")
+    }
+
+    /// TC-073: Switch between all 6 voting layouts without crashing.
+    func testVotingLayouts_AllSelectable() {
+        let tabBar = TabBarScreen(app: app)
+        let settingsScreen = tabBar.tapSettings()
+        settingsScreen.assertVisible()
+
+        // Voting layout names (from VotingLayoutStyle enum)
+        let layouts = ["Horizontal", "Cards", "Stacked", "Aura", "Orbit", "Neon"]
+
+        for layout in layouts {
+            let button = app.buttons["customize_voting_\(layout.lowercased())"]
+            if button.waitForExistence(timeout: 2) {
+                button.tap()
+            } else {
+                // Scroll right to find it
+                app.swipeLeft()
+                if button.waitForExistence(timeout: 2) {
+                    button.tap()
+                }
+            }
+        }
+
+        captureScreenshot(name: "voting_layouts_cycled")
+
+        // Navigate to Day tab to verify the voting layout renders
+        tabBar.tapDay()
+
+        let moodHeader = app.otherElements["mood_header"]
+        // Header may or may not be visible depending on whether today has been voted
+        // Either way, no crash is the main assertion
+        captureScreenshot(name: "day_view_after_layout_change")
+    }
+
+    /// TC-074: Switch between several day view styles without crashing.
+    func testDayViewStyles_MultipleSelectable() {
+        let tabBar = TabBarScreen(app: app)
+        let settingsScreen = tabBar.tapSettings()
+        settingsScreen.assertVisible()
+
+        // Test a representative sample of day view styles (testing all 20+ would be slow)
+        let styles = ["Classic", "Minimal", "Compact", "Bubble", "Grid", "Neon"]
+
+        for style in styles {
+            let button = app.buttons["customize_daystyle_\(style.lowercased())"]
+            if button.waitForExistence(timeout: 2) {
+                button.tap()
+            } else {
+                // Scroll to find it
+                app.swipeLeft()
+                if button.waitForExistence(timeout: 2) {
+                    button.tap()
+                }
+            }
+        }
+
+        captureScreenshot(name: "day_styles_cycled")
+
+        // Navigate to Day tab to verify the style renders with data
+        tabBar.tapDay()
+
+        let entryRow = app.descendants(matching: .any)
+            .matching(NSPredicate(format: "identifier BEGINSWITH %@", "entry_row_"))
+            .firstMatch
+        XCTAssertTrue(
+            entryRow.waitForExistence(timeout: 5),
+            "Entry row should be visible with the new style"
+        )
+
+        captureScreenshot(name: "day_view_after_style_change")
+    }
+}