fix(ios): use deterministic predictive notification identifiers

Replace reminder_* and random test alarm IDs with predictive_<Int>
so UNUserNotificationCenter replaces pending requests instead of
stacking. Daily reminders key off local HH:mm; testAlarm uses the
scheduled fire second. Dual notification id unchanged.

ios/Plugin/DailyNotificationPlugin.swift

@@ -32,7 +32,9 @@ public class DailyNotificationPlugin: CAPPlugin {
     // Background task identifiers
     private let fetchTaskIdentifier = "org.timesafari.dailynotification.fetch"
     private let notifyTaskIdentifier = "org.timesafari.dailynotification.notify"
-    /// Stable identifier for the dual (New Activity) user notification. Used for replace and cancelDualSchedule; must not conflict with Daily Reminder (`reminder_<id>`).
+    /// Prefix for deterministic UNNotificationRequest identifiers built as `predictive_\(Int(timestamp))` so rescheduling the same slot replaces instead of stacking.
+    private let predictiveNotificationPrefix = "predictive_"
+    /// Stable identifier for the dual (New Activity) user notification. Used for replace and cancelDualSchedule; must not conflict with Daily Reminder (`predictive_*`).
     private let dualNotificationRequestIdentifier = "org.timesafari.dailynotification.dual"
     /// UserDefaults key for persisted dual schedule config (userNotification + relationship) for relationship resolution when fetch completes.
     private let dualScheduleConfigKey = "dual_schedule_config"
@@ -428,7 +430,7 @@ public class DailyNotificationPlugin: CAPPlugin {
         }
     }
     
-    /// Cancel the dual (New Activity) schedule only. Does not affect Daily Reminder (reminder_*).
+    /// Cancel the dual (New Activity) schedule only. Does not affect Daily Reminder (`predictive_*`).
     @objc func cancelDualSchedule(_ call: CAPPluginCall) {
         do {
             performCancelDualSchedule()
@@ -1083,6 +1085,28 @@ public class DailyNotificationPlugin: CAPPlugin {
         return interval > 0 ? interval : (24 * 60 * 60)
     }
 
+    /// Seconds since local midnight for the daily reminder slot; stable for the same HH:mm so re-schedules overwrite.
+    private func predictiveReminderTimestamp(hour: Int, minute: Int) -> Int {
+        hour * 3600 + minute * 60
+    }
+
+    private func predictiveReminderRequestId(hour: Int, minute: Int) -> String {
+        let timestamp = predictiveReminderTimestamp(hour: hour, minute: minute)
+        return "\(predictiveNotificationPrefix)\(timestamp)"
+    }
+
+    private func predictiveReminderRequestId(fromTimeHHmm time: String) -> String? {
+        let timeComponents = time.components(separatedBy: ":")
+        guard timeComponents.count == 2,
+              let hour = Int(timeComponents[0]),
+              let minute = Int(timeComponents[1]),
+              hour >= 0, hour <= 23,
+              minute >= 0, minute <= 59 else {
+            return nil
+        }
+        return predictiveReminderRequestId(hour: hour, minute: minute)
+    }
+
     // MARK: - Static Daily Reminder Methods
 
     @objc func scheduleDailyReminder(_ call: CAPPluginCall) {
@@ -1140,8 +1164,9 @@ public class DailyNotificationPlugin: CAPPlugin {
             repeats: repeatDaily
         )
 
+        let requestId = predictiveReminderRequestId(hour: hour, minute: minute)
         let request = UNNotificationRequest(
-            identifier: "reminder_\(id)",
+            identifier: requestId,
             content: content,
             trigger: trigger
         )
@@ -1177,8 +1202,13 @@ public class DailyNotificationPlugin: CAPPlugin {
             return
         }
 
-        // Cancel the notification
+        // Cancel the notification (deterministic id from stored HH:mm)
-        notificationCenter.removePendingNotificationRequests(withIdentifiers: ["reminder_\(reminderId)"])
+        let reminders = getRemindersFromUserDefaults()
+        if let stored = reminders.first(where: { ($0["id"] as? String) == reminderId }),
+           let time = stored["time"] as? String,
+           let requestId = predictiveReminderRequestId(fromTimeHHmm: time) {
+            notificationCenter.removePendingNotificationRequests(withIdentifiers: [requestId])
+        }
 
         // Delegate to storage for reminder removal
         removeReminderFromUserDefaults(id: reminderId)
@@ -1191,14 +1221,18 @@ public class DailyNotificationPlugin: CAPPlugin {
 
         // Get pending notifications
         notificationCenter.getPendingNotificationRequests { requests in
-            let reminderRequests = requests.filter { $0.identifier.hasPrefix("reminder_") }
+            let reminderRequests = requests.filter { $0.identifier.hasPrefix(self.predictiveNotificationPrefix) }
 
             // Get stored reminder data from UserDefaults
             let reminders = self.getRemindersFromUserDefaults()
 
             var result: [[String: Any]] = []
             for reminder in reminders {
-                let isScheduled = reminderRequests.contains { $0.identifier == "reminder_\(reminder["id"] as! String)" }
+                let expectedId: String? = {
+                    guard let time = reminder["time"] as? String else { return nil }
+                    return self.predictiveReminderRequestId(fromTimeHHmm: time)
+                }()
+                let isScheduled = reminderRequests.contains { expectedId != nil && $0.identifier == expectedId }
                 var reminderInfo = reminder
                 reminderInfo["isScheduled"] = isScheduled
                 result.append(reminderInfo)
@@ -1216,8 +1250,13 @@ public class DailyNotificationPlugin: CAPPlugin {
             return
         }
 
-        // Cancel existing reminder
+        // Cancel existing reminder (slot before UserDefaults update)
-        notificationCenter.removePendingNotificationRequests(withIdentifiers: ["reminder_\(reminderId)"])
+        let remindersBeforeUpdate = getRemindersFromUserDefaults()
+        if let stored = remindersBeforeUpdate.first(where: { ($0["id"] as? String) == reminderId }),
+           let oldTime = stored["time"] as? String,
+           let oldRequestId = predictiveReminderRequestId(fromTimeHHmm: oldTime) {
+            notificationCenter.removePendingNotificationRequests(withIdentifiers: [oldRequestId])
+        }
 
         // Update in UserDefaults
         let title = call.getString("title")
@@ -1282,8 +1321,9 @@ public class DailyNotificationPlugin: CAPPlugin {
                 repeats: repeatDaily ?? true
             )
 
+            let requestId = predictiveReminderRequestId(hour: hour, minute: minute)
             let request = UNNotificationRequest(
-                identifier: "reminder_\(reminderId)",
+                identifier: requestId,
                 content: content,
                 trigger: trigger
             )
@@ -1540,10 +1580,11 @@ public class DailyNotificationPlugin: CAPPlugin {
                 // Create time interval trigger (fires in X seconds)
                 let trigger = UNTimeIntervalNotificationTrigger(timeInterval: TimeInterval(validSeconds), repeats: false)
                 
-                // Create notification request with unique ID
+                // Deterministic id from scheduled fire time (Unix seconds) so repeat scheduling replaces instead of stacking
-                let notificationId = "test_alarm_\(Date().timeIntervalSince1970)"
+                let timestamp = Int(Date().timeIntervalSince1970) + validSeconds
+                let requestId = "\(predictiveNotificationPrefix)\(timestamp)"
                 let request = UNNotificationRequest(
-                    identifier: notificationId,
+                    identifier: requestId,
                     content: notificationContent,
                     trigger: trigger
                 )