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/Screens/DayScreen.swift

@@ -33,11 +33,11 @@ struct DayScreen {
     /// Tap a mood button by mood name. Waits for the celebration animation to complete.
     func logMood(_ mood: MoodChoice, file: StaticString = #file, line: UInt = #line) {
         let button = moodButton(for: mood)
-        guard button.waitUntilHittable(timeout: 5) else {
-            XCTFail("Mood button '\(mood.rawValue)' not hittable", file: file, line: line)
+        guard button.waitForExistence(timeout: 5) else {
+            XCTFail("Mood button '\(mood.rawValue)' not found", file: file, line: line)
             return
         }
-        button.tap()
+        button.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
 
         // Wait for the celebration animation to finish and entry to appear.
         // The mood header disappears after logging today's mood.