Add email notification preference for task completion

- Add emailTaskCompleted field to NotificationPreference model
- Add email preference toggle to notification settings UI (iOS & Android)
- Add localized strings for email notifications section
- Update ViewModel to support email preference updates

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

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

iosApp/iosApp/Helpers/L10n.swift

@@ -540,6 +540,11 @@ enum L10n {
         static var warrantyExpiring: String { String(localized: "profile_warranty_expiring") }
         static var warrantyExpiringDescription: String { String(localized: "profile_warranty_expiring_description") }
         static var otherNotifications: String { String(localized: "profile_other_notifications") }
+
+        // Email Notifications
+        static var emailNotifications: String { String(localized: "profile_email_notifications") }
+        static var emailTaskCompleted: String { String(localized: "profile_email_task_completed") }
+        static var emailTaskCompletedDescription: String { String(localized: "profile_email_task_completed_description") }
     }
 
     // MARK: - Settings

iosApp/iosApp/Localizable.xcstrings

@@ -17844,6 +17844,17 @@
         }
       }
     },
+    "profile_email_notifications" : {
+      "extractionState" : "manual",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Email Notifications"
+          }
+        }
+      }
+    },
     "profile_email_required_unique" : {
       "extractionState" : "manual",
       "localizations" : {
@@ -17909,6 +17920,28 @@
         }
       }
     },
+    "profile_email_task_completed" : {
+      "extractionState" : "manual",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Task Completed Email"
+          }
+        }
+      }
+    },
+    "profile_email_task_completed_description" : {
+      "extractionState" : "manual",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Receive email when a task is completed"
+          }
+        }
+      }
+    },
     "profile_first_name" : {
       "extractionState" : "manual",
       "localizations" : {

iosApp/iosApp/Profile/NotificationPreferencesView.swift

@@ -191,6 +191,31 @@ struct NotificationPreferencesView: View {
                         Text(L10n.Profile.otherNotifications)
                     }
                     .listRowBackground(Color.appBackgroundSecondary)
+
+                    // Email Notifications
+                    Section {
+                        Toggle(isOn: $viewModel.emailTaskCompleted) {
+                            Label {
+                                VStack(alignment: .leading, spacing: 2) {
+                                    Text(L10n.Profile.emailTaskCompleted)
+                                        .foregroundColor(Color.appTextPrimary)
+                                    Text(L10n.Profile.emailTaskCompletedDescription)
+                                        .font(.caption)
+                                        .foregroundColor(Color.appTextSecondary)
+                                }
+                            } icon: {
+                                Image(systemName: "envelope.fill")
+                                    .foregroundColor(Color.appPrimary)
+                            }
+                        }
+                        .tint(Color.appPrimary)
+                        .onChange(of: viewModel.emailTaskCompleted) { _, newValue in
+                            viewModel.updatePreference(emailTaskCompleted: newValue)
+                        }
+                    } header: {
+                        Text(L10n.Profile.emailNotifications)
+                    }
+                    .listRowBackground(Color.appBackgroundSecondary)
                 }
             }
             .listStyle(.plain)
@@ -223,6 +248,7 @@ class NotificationPreferencesViewModelWrapper: ObservableObject {
     @Published var taskAssigned: Bool = true
     @Published var residenceShared: Bool = true
     @Published var warrantyExpiring: Bool = true
+    @Published var emailTaskCompleted: Bool = true
 
     @Published var isLoading: Bool = false
     @Published var errorMessage: String?
@@ -243,6 +269,7 @@ class NotificationPreferencesViewModelWrapper: ObservableObject {
                     self.taskAssigned = prefs.taskAssigned
                     self.residenceShared = prefs.residenceShared
                     self.warrantyExpiring = prefs.warrantyExpiring
+                    self.emailTaskCompleted = prefs.emailTaskCompleted
                     self.isLoading = false
                     self.errorMessage = nil
                 } else if let error = result as? ApiResultError {
@@ -262,7 +289,8 @@ class NotificationPreferencesViewModelWrapper: ObservableObject {
         taskCompleted: Bool? = nil,
         taskAssigned: Bool? = nil,
         residenceShared: Bool? = nil,
-        warrantyExpiring: Bool? = nil
+        warrantyExpiring: Bool? = nil,
+        emailTaskCompleted: Bool? = nil
     ) {
         isSaving = true
 
@@ -274,7 +302,8 @@ class NotificationPreferencesViewModelWrapper: ObservableObject {
                     taskCompleted: taskCompleted.map { KotlinBoolean(bool: $0) },
                     taskAssigned: taskAssigned.map { KotlinBoolean(bool: $0) },
                     residenceShared: residenceShared.map { KotlinBoolean(bool: $0) },
-                    warrantyExpiring: warrantyExpiring.map { KotlinBoolean(bool: $0) }
+                    warrantyExpiring: warrantyExpiring.map { KotlinBoolean(bool: $0) },
+                    emailTaskCompleted: emailTaskCompleted.map { KotlinBoolean(bool: $0) }
                 )
                 let result = try await APILayer.shared.updateNotificationPreferences(request: request)