Fix accessibility IDs and settings scroll for remaining test failures

- Added month_grid accessibility ID to MonthView ScrollView
- Added year_heatmap accessibility ID to YearView ScrollView
- Fixed DayScreen.assertVisible() to accept entry rows OR mood header
- Fixed DataPersistenceTests for in-memory storage (fixture re-seeds)
- Fixed AppLaunchTests to use week_of_moods fixture (empty has no grid)
- Fixed SettingsScreen segmented control tap with multi-strategy fallback
- Improved settings scroll with coordinate-based swipe for deep elements
- OnboardingScreen swipeToNext uses slow velocity for paged TabView

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Tests iOS/SettingsActionTests.swift

@@ -23,9 +23,7 @@ final class SettingsActionTests: BaseUITestCase {
         settingsScreen.assertVisible()
         settingsScreen.tapSettingsTab()
 
-        // Scroll to and tap Clear All Data
-        settingsScreen.clearDataButton
-            .scrollIntoView(in: app.scrollViews.firstMatch, direction: .up)
+        // Scroll to and tap Clear All Data (tapClearData handles scrolling)
         settingsScreen.tapClearData()
 
         // Navigate back to Day tab
@@ -52,9 +50,7 @@ final class SettingsActionTests: BaseUITestCase {
         settingsScreen.assertVisible()
         settingsScreen.tapSettingsTab()
 
-        // Scroll to analytics toggle and tap it
-        settingsScreen.analyticsToggle
-            .scrollIntoView(in: app.scrollViews.firstMatch, direction: .up)
+        // Scroll to analytics toggle and tap it (tapAnalyticsToggle handles scrolling)
         settingsScreen.tapAnalyticsToggle()
 
         captureScreenshot(name: "analytics_toggled")