Add comprehensive WCAG 2.1 AA accessibility support

- Add VoiceOver labels and hints to all voting layouts, settings, widgets,
  onboarding screens, and entry cells
- Add Reduce Motion support to button animations throughout the app
- Ensure 44x44pt minimum touch targets on widget mood buttons
- Enhance AccessibilityHelpers with Dynamic Type support, ScaledValue wrapper,
  and VoiceOver detection utilities
- Gate premium features (Insights, Month/Year views) behind subscription
- Update widgets to show subscription prompts for non-subscribers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Views/CustomizeView/SubViews/DayFilterPickerView.swift

@@ -29,17 +29,24 @@ struct DayFilterPickerView: View {
                     ForEach(weekdays.indices, id: \.self) { dayIdx in
                         let day = String(weekdays[dayIdx].0)
                         let value = weekdays[dayIdx].1
-                        Button(day.capitalized, action: {
-                            if filteredDays.currentFilters.contains(value) {
+                        let isSelected = filteredDays.currentFilters.contains(value)
+                        Button(action: {
+                            if isSelected {
                                 filteredDays.removeFilter(filter: value)
                             } else {
                                 filteredDays.addFilter(newFilter: value)
                             }
                             let impactMed = UIImpactFeedbackGenerator(style: .heavy)
                             impactMed.impactOccurred()
-                        })
-                        .frame(maxWidth: .infinity)
-                        .foregroundColor(filteredDays.currentFilters.contains(value) ? .green : .red)
+                        }) {
+                            Text(day.capitalized)
+                                .frame(maxWidth: .infinity)
+                                .padding(.vertical, 12)
+                                .background(Color(uiColor: .tertiarySystemBackground))
+                                .foregroundColor(isSelected ? .green : .red)
+                                .cornerRadius(8)
+                        }
+                        .buttonStyle(.plain)
                     }
                 }
                 Text(String(localized: "day_picker_view_text"))