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/SecondaryTabTests.swift

@@ -0,0 +1,51 @@
+//
+//  SecondaryTabTests.swift
+//  Tests iOS
+//
+//  Month, Year, and Insights tab navigation tests.
+//
+
+import XCTest
+
+final class SecondaryTabTests: BaseUITestCase {
+    override var seedFixture: String? { "week_of_moods" }
+
+    /// Navigate to Month tab and verify content loads.
+    func testMonthTab_LoadsContent() {
+        let tabBar = TabBarScreen(app: app)
+        tabBar.tapMonth()
+
+        // Month view should have some content loaded — look for the "Month" header text
+        // or the month grid area. The tab should at minimum be selected.
+        XCTAssertTrue(tabBar.monthTab.isSelected, "Month tab should be selected")
+
+        captureScreenshot(name: "month_tab")
+    }
+
+    /// Navigate to Year tab and verify content loads.
+    func testYearTab_LoadsContent() {
+        let tabBar = TabBarScreen(app: app)
+        tabBar.tapYear()
+
+        XCTAssertTrue(tabBar.yearTab.isSelected, "Year tab should be selected")
+
+        captureScreenshot(name: "year_tab")
+    }
+
+    /// Navigate to Insights tab and verify the header is visible.
+    func testInsightsTab_ShowsHeader() {
+        let tabBar = TabBarScreen(app: app)
+        tabBar.tapInsights()
+
+        XCTAssertTrue(tabBar.insightsTab.isSelected, "Insights tab should be selected")
+
+        // Verify the Insights header text is visible
+        let insightsHeader = app.staticTexts["insights_header"]
+        XCTAssertTrue(
+            insightsHeader.waitForExistence(timeout: 5),
+            "Insights header should be visible"
+        )
+
+        captureScreenshot(name: "insights_tab")
+    }
+}