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/MonthViewInteractionTests.swift

@@ -0,0 +1,88 @@
+//
+//  MonthViewInteractionTests.swift
+//  Tests iOS
+//
+//  Month view interaction tests — tapping into month content.
+//
+
+import XCTest
+
+final class MonthViewInteractionTests: BaseUITestCase {
+    override var seedFixture: String? { "week_of_moods" }
+
+    /// TC-030: Tap on month view content and verify interaction works without crash.
+    func testMonthView_TapContent_NoCrash() {
+        let tabBar = TabBarScreen(app: app)
+
+        // 1. Navigate to Month tab
+        tabBar.tapMonth()
+        XCTAssertTrue(tabBar.monthTab.isSelected, "Month tab should be selected")
+
+        // 2. Wait for month grid content to load
+        let monthGrid = app.otherElements["month_grid"]
+        let scrollView = app.scrollViews.firstMatch
+
+        // Either the month_grid identifier or a scroll view should be present
+        let contentLoaded = monthGrid.waitForExistence(timeout: 5) ||
+                            scrollView.waitForExistence(timeout: 5)
+        XCTAssertTrue(contentLoaded, "Month view should have loaded content")
+
+        captureScreenshot(name: "month_view_before_tap")
+
+        // 3. Tap on the month view content (first cell/card in the grid)
+        //    Try the month_grid element first; fall back to tapping the scroll view content
+        if monthGrid.exists && monthGrid.isHittable {
+            monthGrid.tap()
+        } else if scrollView.exists && scrollView.isHittable {
+            // Tap near the center of the scroll view to hit a month card
+            scrollView.tap()
+        }
+
+        // 4. Verify the app did not crash — the tab bar should still be accessible
+        XCTAssertTrue(
+            tabBar.monthTab.waitForExistence(timeout: 5),
+            "App should remain stable after tapping month content"
+        )
+
+        // 5. Check if any detail/navigation occurred (look for navigation bar or content change)
+        //    Month view may show a detail view or popover depending on the card tapped
+        let navBar = app.navigationBars.firstMatch
+        let detailAppeared = navBar.waitForExistence(timeout: 3)
+
+        if detailAppeared {
+            captureScreenshot(name: "month_detail_view")
+        } else {
+            // No navigation occurred, which is also valid — the main check is no crash
+            captureScreenshot(name: "month_view_after_tap")
+        }
+    }
+
+    /// Navigate to Month tab with data, scroll down, and verify no crash.
+    func testMonthView_Scroll_NoCrash() {
+        let tabBar = TabBarScreen(app: app)
+
+        // Navigate to Month tab
+        tabBar.tapMonth()
+        XCTAssertTrue(tabBar.monthTab.isSelected, "Month tab should be selected")
+
+        // Wait for content to load
+        let scrollView = app.scrollViews.firstMatch
+        guard scrollView.waitForExistence(timeout: 5) else {
+            // If no scroll view, the month view may use a different layout — verify no crash
+            XCTAssertTrue(tabBar.monthTab.exists, "App should not crash on month view")
+            return
+        }
+
+        // Scroll down and up
+        scrollView.swipeUp()
+        scrollView.swipeDown()
+
+        // Verify the app is still stable
+        XCTAssertTrue(
+            tabBar.monthTab.waitForExistence(timeout: 3),
+            "App should remain stable after scrolling month view"
+        )
+
+        captureScreenshot(name: "month_view_after_scroll")
+    }
+}