iOS VoiceOver accessibility overhaul — 67 files

New framework:
- AccessibilityLabels.swift: centralized A11y struct with VoiceOver strings
- AccessibilityModifiers.swift: reusable .a11yHeader, .a11yDecorative,
  .a11yButton, .a11yCard, .a11yStatValue View extensions

Shared components: decorative elements hidden, stat views combined,
status/priority badges labeled, error views announced, empty states grouped

Cards: ResidenceCard, TaskCard, DynamicTaskCard, ContractorCard,
DocumentCard, WarrantyCard — all grouped with combined labels,
chevrons hidden, action buttons labeled

Main screens: Login, Register, Residences, Tasks, Contractors, Documents —
toolbar buttons labeled, section headers marked, form field hints added

Onboarding: all 10 views — header traits, button hints, task selection
state, progress indicator, decorative backgrounds hidden

Profile/Subscription: toggle hints, theme selection state, feature
comparison table accessibility, subscription button labels

iOS build verified: BUILD SUCCEEDED

iosApp/iosApp/Task/CompleteTaskView.swift

@@ -180,6 +180,18 @@ struct CompleteTaskView: View {
                         .frame(maxWidth: .infinity)
                     }
                     .accessibilityIdentifier(AccessibilityIdentifiers.Task.ratingView)
+                    .accessibilityElement(children: .combine)
+                    .accessibilityLabel("Rating: \(rating) out of 5 stars")
+                    .accessibilityAdjustableAction { direction in
+                        switch direction {
+                        case .increment:
+                            if rating < 5 { rating += 1 }
+                        case .decrement:
+                            if rating > 1 { rating -= 1 }
+                        @unknown default:
+                            break
+                        }
+                    }
                 } footer: {
                     Text(L10n.Tasks.rateQuality)
                 }