Fix remaining 17 UI test failures: group defaults, identifiers, hittability, date format

- resetAppState: use correct suite name to clear group defaults (fixes stale subscription state)
- Reorder configureIfNeeded: set expireTrial before IAPManager init
- Add browse_themes_button identifier to CustomizeView Browse Themes button
- Add mood_button_* identifiers to Entry Detail mood grid in NoteEditorView
- Use coordinate-based tap throughout all test screens (iOS 26 Liquid Glass hittability)
- Fix HeaderMoodLogging date format: M/d/yyyy → yyyy/MM/dd to match entry_row identifiers
- AppLaunchTests: wait for isSelected state with NSPredicate instead of immediate check
- OnboardingTests: add waits between swipes and retry logic for skip button

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Tests iOS/PremiumCustomizationTests.swift

@@ -54,7 +54,7 @@ final class PremiumCustomizationTests: BaseUITestCase {
             subscribeButton.waitForExistence(timeout: 5),
             "Subscribe button should exist"
         )
-        subscribeButton.tapWhenReady()
+        subscribeButton.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
 
         // Verify the subscription sheet appears — look for common subscription
         // sheet elements (subscription store view or paywall content).