Add missing accessibility identifiers to all interactive UI elements

Audit found ~50+ interactive elements (buttons, toggles, pickers, alerts,
links) missing accessibility identifiers across 13 view files. Added
centralized ID definitions and applied them to every entry detail button,
guided reflection control, settings toggle, paywall unlock button,
subscription/IAP button, lock screen control, and photo action dialog.

Shared/Views/MonthView/MonthDetailView.swift

@@ -54,6 +54,7 @@ struct MonthDetailView: View {
                 Image(systemName: "square.and.arrow.up")
                     .foregroundColor(textColor)
                     .padding(.trailing)
+                    .accessibilityIdentifier(AccessibilityID.MonthDetail.shareButton)
                     .onTapGesture {
                         let impactMed = UIImpactFeedbackGenerator(style: .heavy)
                         impactMed.impactOccurred()
@@ -97,6 +98,7 @@ struct MonthDetailView: View {
                     showUpdateEntryAlert = false
                     selectedEntry = nil
                 })
+                .accessibilityIdentifier(AccessibilityID.MonthDetail.moodButton(mood.strValue))
             }
 
             if let selectedEntry = selectedEntry,
@@ -107,6 +109,7 @@ struct MonthDetailView: View {
                     updateEntries()
                     showUpdateEntryAlert = false
                 })
+                .accessibilityIdentifier(AccessibilityID.MonthDetail.deleteButton)
             }
 
             Button(String(localized: "content_view_fill_in_missing_entry_cancel"), role: .cancel,  action: {

Shared/Views/MonthView/MonthView.swift

@@ -324,6 +324,7 @@ struct MonthView: View {
                         .clipShape(RoundedRectangle(cornerRadius: 14))
                     }
                     .padding(.horizontal, 24)
+                    .accessibilityIdentifier(AccessibilityID.Paywall.monthUnlockButton)
                 }
                 .padding(.vertical, 24)
                 .frame(maxWidth: .infinity)