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/MoodLoggingWithDataTests.swift

@@ -0,0 +1,38 @@
+//
+//  MoodLoggingWithDataTests.swift
+//  Tests iOS
+//
+//  Mood logging with existing seeded data tests.
+//
+
+import XCTest
+
+final class MoodLoggingWithDataTests: BaseUITestCase {
+    override var seedFixture: String? { "week_of_moods" }
+
+    /// With a week of data seeded, the mood header should appear if today is missing a vote.
+    /// Log a new mood and verify header disappears.
+    func testLogMood_Average_WhenDataExists() {
+        let dayScreen = DayScreen(app: app)
+
+        // The seeded data includes today (offset 0 = great).
+        // After reset + seed, today already has an entry, so header may be hidden.
+        // If the header IS visible (i.e. vote logic says "needs vote"), tap it.
+        if dayScreen.moodHeader.waitForExistence(timeout: 3) {
+            dayScreen.logMood(.average)
+            // After logging, header should disappear (today is now voted)
+            dayScreen.assertMoodHeaderHidden()
+        }
+
+        // Regardless, verify at least one entry row is visible (seeded data)
+        let anyEntry = app.descendants(matching: .any)
+            .matching(NSPredicate(format: "identifier BEGINSWITH %@", "entry_row_"))
+            .firstMatch
+        XCTAssertTrue(
+            anyEntry.waitForExistence(timeout: 5),
+            "At least one entry row should exist from seeded data"
+        )
+
+        captureScreenshot(name: "mood_logged_with_data")
+    }
+}