refactor(calendar): group calendars by accounts in settings

Calendars in the "Select Calendars" settings section are now grouped by their source account with color indicators, making it possible to distinguish calendars that share the same name across different accounts.

Each account group header includes a toggle to select or deselect all calendars in that group.

DynamicIsland/Providers/CalendarServiceProviding.swift

@@ -146,6 +146,7 @@ class CalendarService: CalendarServiceProviding {
 extension CalendarModel {
     init(from calendar: EKCalendar) {
         self.init(
+            accountName: calendar.accountTitle,
             id: calendar.calendarIdentifier,
             title: calendar.title,
             color: calendar.color,
@@ -267,7 +268,7 @@ extension Priority {
 
 // MARK: - Helper Extensions
 
-private extension EKCalendar {
+extension EKCalendar {
     var accountTitle: String {
         switch source.sourceType {
         case .local, .subscribed, .birthdays:

DynamicIsland/components/Settings/SettingsView.swift

@@ -2905,18 +2905,48 @@ struct CalendarSettings: View {
                 }
 
                 Section(header: Text("Select Calendars")) {
-                    ForEach(calendarManager.allCalendars, id: \.id) { calendar in
-                        Toggle(isOn: Binding(
-                            get: { calendarManager.getCalendarSelected(calendar) },
-                            set: { isSelected in
-                                Task {
-                                    await calendarManager.setCalendarSelected(calendar, isSelected: isSelected)
+                    let grouped = Dictionary(grouping: calendarManager.allCalendars, by: \.accountName)
+                    let sortedAccounts = grouped.keys.sorted()
+
+                    ForEach(sortedAccounts, id: \.self) { account in
+                        let accountCalendars = grouped[account] ?? []
+                        let allAccountSelected = accountCalendars.allSatisfy { calendarManager.getCalendarSelected($0) }
+
+                        Section(header: HStack {
+                            Text(account)
+                            Spacer()
+                            Toggle("", isOn: Binding(
+                                get: { allAccountSelected },
+                                set: { isSelected in
+                                    Task {
+                                        await calendarManager.setCalendarsSelected(accountCalendars, isSelected: isSelected)
+                                    }
                                 }
+                            ))
+                            .labelsHidden()
+                            .toggleStyle(.switch)
+                            .controlSize(.mini)
+                            .disabled(!showCalendar)
+                        }) {
+                            ForEach(accountCalendars, id: \.id) { calendar in
+                                Toggle(isOn: Binding(
+                                    get: { calendarManager.getCalendarSelected(calendar) },
+                                    set: { isSelected in
+                                        Task {
+                                            await calendarManager.setCalendarSelected(calendar, isSelected: isSelected)
+                                        }
+                                    }
+                                )) {
+                                    HStack(spacing: 8) {
+                                        Circle()
+                                            .fill(Color(calendar.color))
+                                            .frame(width: 8, height: 8)
+                                        Text(calendar.title)
+                                    }
+                                }
+                                .disabled(!showCalendar)
                             }
-                        )) {
-                            Text(calendar.title)
                         }
-                        .disabled(!showCalendar)
                     }
                 }
             }

DynamicIsland/managers/CalendarManager.swift

@@ -382,6 +382,36 @@ class CalendarManager: ObservableObject {
         lastEventsFetchDate = Date()
     }
 
+    func setCalendarsSelected(_ calendars: [CalendarModel], isSelected: Bool) async {
+        var selectionState = Defaults[.calendarSelectionState]
+        let ids = Set(calendars.map { $0.id })
+
+        switch selectionState {
+        case .all:
+            if !isSelected {
+                let identifiers = Set(allCalendars.map { $0.id }).subtracting(ids)
+                selectionState = .selected(identifiers)
+            }
+        case .selected(var identifiers):
+            if isSelected {
+                identifiers.formUnion(ids)
+            } else {
+                identifiers.subtract(ids)
+            }
+
+            if identifiers.isEmpty || identifiers.count == allCalendars.count {
+                selectionState = .all
+            } else {
+                selectionState = .selected(identifiers)
+            }
+        }
+
+        Defaults[.calendarSelectionState] = selectionState
+        updateSelectedCalendars()
+        await updateEvents(force: true)
+        await updateLockScreenEvents(force: true)
+    }
+
     func setReminderCompleted(reminderID: String, completed: Bool) async {
         await calendarService.setReminderCompleted(reminderID: reminderID, completed: completed)
         await updateEvents(force: true)

DynamicIsland/managers/LockScreenWidgetPreviewManager.swift

@@ -302,6 +302,7 @@ final class LockScreenWidgetPreviewManager: ObservableObject {
     private func applyCalendarPreviewEvents() {
         let now = Date()
         let reminderCalendar = CalendarModel(
+            accountName: "Preview",
             id: "preview.reminders",
             title: "Reminders",
             color: .systemBlue,
@@ -327,6 +328,7 @@ final class LockScreenWidgetPreviewManager: ObservableObject {
         )
 
         let eventCalendar = CalendarModel(
+            accountName: "Preview",
             id: "preview.calendar",
             title: "Calendar",
             color: .systemOrange,

DynamicIsland/models/CalendarModel.swift

@@ -23,6 +23,7 @@
 import Cocoa
 
 struct CalendarModel: Identifiable, Hashable {
+    let accountName: String
     let id: String
     let title: String
     let color: NSColor