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>

Shared/Views/CustomizeView/CustomizeView.swift

@@ -278,6 +278,7 @@ struct ThemePickerCompact: View {
                     }
                 }
                 .buttonStyle(BorderlessButtonStyle())
+                .accessibilityIdentifier(AccessibilityID.Customize.themeButton(aTheme.title))
             }
             Spacer()
         }
@@ -331,6 +332,7 @@ struct ImagePackPickerCompact: View {
                     )
                 }
                 .buttonStyle(.plain)
+                .accessibilityIdentifier(AccessibilityID.Customize.iconPackButton("\(images)"))
             }
         }
     }
@@ -379,6 +381,7 @@ struct VotingLayoutPickerCompact: View {
                         )
                     }
                     .buttonStyle(.plain)
+                    .accessibilityIdentifier(AccessibilityID.Customize.votingLayoutButton(layout.displayName))
                 }
             }
             .padding(.horizontal, 4)
@@ -742,6 +745,7 @@ struct DayViewStylePickerCompact: View {
                         )
                     }
                     .buttonStyle(.plain)
+                    .accessibilityIdentifier(AccessibilityID.Customize.dayViewStyleButton(style.displayName))
                 }
             }
             .padding(.horizontal, 4)

Shared/Views/CustomizeView/SubViews/AppThemePickerView.swift

@@ -214,6 +214,7 @@ struct AppThemeCard: View {
             )
         }
         .buttonStyle(.plain)
+        .accessibilityIdentifier(AccessibilityID.Customize.appThemeCard(theme.name))
     }
 }