Complete accessibility identifier coverage across all 152 project files

Exhaustive file-by-file audit of every Swift file in the project (iOS app,
Watch app, Widget extension). Every interactive UI element — buttons, toggles,
pickers, links, menus, tap gestures, text editors, color pickers, photo
pickers — now has an accessibilityIdentifier for XCUITest automation.

46 files changed across Shared/, Onboarding/, Watch App/, and Widget targets.
Added ~100 new ID definitions covering settings debug controls, export/photo
views, sharing templates, customization subviews, onboarding flows, tip
modals, widget voting buttons, and watch mood buttons.

Shared/Onboarding/views/OnboardingTime.swift

@@ -65,6 +65,7 @@ struct OnboardingTime: View {
                         .datePickerStyle(.wheel)
                         .labelsHidden()
                         .colorScheme(.light)
+                        .accessibilityIdentifier(AccessibilityID.Onboarding.timePicker)
                         .accessibilityLabel(String(localized: "Reminder time"))
                         .accessibilityHint(String(localized: "Select when you want to be reminded"))
                 }