feat(plugin): add optional rolloverIntervalMinutes for dev/testing

Add optional rolloverIntervalMinutes to scheduleDailyNotification so the
next occurrence can be scheduled N minutes after the current trigger
(e.g. 10 minutes) instead of 24 hours. Value is persisted and used on
rollover and after reboot.

- TypeScript: NotificationOptions.rolloverIntervalMinutes?: number
- Android: Schedule.rolloverIntervalMinutes in Room (migration 2→3);
  Plugin and ScheduleHelper persist it; Worker uses it in rollover and
  updates nextRunAt; ReactivationManager uses it in boot recovery
- iOS: NotificationContent.rolloverIntervalMinutes (Codable); Plugin
  passes it into content; Scheduler uses it in calculateNextScheduledTime
  and copies to nextContent on rollover

When absent or ≤0, behavior unchanged (24h). App can clear by calling
scheduleDailyNotification without the parameter.

ios/Plugin/NotificationContent.swift

@@ -27,6 +27,8 @@ class NotificationContent: Codable {
     let url: String?
     let payload: [String: Any]?
     let etag: String?
+    /** When > 0, next occurrence is this many minutes after trigger (dev/testing). Nil/0 = 24h. Persisted for rollover and recovery. */
+    var rolloverIntervalMinutes: Int?
     
     // Phase 2: Delivery tracking properties
     var deliveryStatus: String? // e.g., "scheduled", "delivered", "missed", "error"
@@ -43,6 +45,7 @@ class NotificationContent: Codable {
         case url
         case payload
         case etag
+        case rolloverIntervalMinutes
         case deliveryStatus
         case lastDeliveryAttempt
     }
@@ -64,6 +67,7 @@ class NotificationContent: Codable {
             payload = nil
         }
         etag = try container.decodeIfPresent(String.self, forKey: .etag)
+        rolloverIntervalMinutes = try container.decodeIfPresent(Int.self, forKey: .rolloverIntervalMinutes)
         deliveryStatus = try container.decodeIfPresent(String.self, forKey: .deliveryStatus)
         lastDeliveryAttempt = try container.decodeIfPresent(Int64.self, forKey: .lastDeliveryAttempt)
     }
@@ -83,6 +87,7 @@ class NotificationContent: Codable {
             try container.encode(payloadString, forKey: .payload)
         }
         try container.encodeIfPresent(etag, forKey: .etag)
+        try container.encodeIfPresent(rolloverIntervalMinutes, forKey: .rolloverIntervalMinutes)
         try container.encodeIfPresent(deliveryStatus, forKey: .deliveryStatus)
         try container.encodeIfPresent(lastDeliveryAttempt, forKey: .lastDeliveryAttempt)
     }
@@ -100,20 +105,21 @@ class NotificationContent: Codable {
      * @param url URL for content fetching
      * @param payload Additional payload data
      * @param etag ETag for HTTP caching
+     * @param rolloverIntervalMinutes When > 0, next occurrence is this many minutes after trigger (dev/testing). Nil/0 = 24h.
      * @param deliveryStatus Delivery status (optional, Phase 2)
      * @param lastDeliveryAttempt Last delivery attempt timestamp (optional, Phase 2)
      */
-    init(id: String, 
-         title: String?, 
-         body: String?, 
-         scheduledTime: Int64, 
-         fetchedAt: Int64, 
-         url: String?, 
-         payload: [String: Any]?, 
+    init(id: String,
+         title: String?,
+         body: String?,
+         scheduledTime: Int64,
+         fetchedAt: Int64,
+         url: String?,
+         payload: [String: Any]?,
          etag: String?,
+         rolloverIntervalMinutes: Int? = nil,
          deliveryStatus: String? = nil,
          lastDeliveryAttempt: Int64? = nil) {
-        
         self.id = id
         self.title = title
         self.body = body
@@ -122,6 +128,7 @@ class NotificationContent: Codable {
         self.url = url
         self.payload = payload
         self.etag = etag
+        self.rolloverIntervalMinutes = rolloverIntervalMinutes
         self.deliveryStatus = deliveryStatus
         self.lastDeliveryAttempt = lastDeliveryAttempt
     }
@@ -259,6 +266,7 @@ class NotificationContent: Codable {
             lastDeliveryAttempt = nil
         }
         
+        let rollover = (dict["rolloverIntervalMinutes"] as? NSNumber)?.intValue
         return NotificationContent(
             id: id,
             title: dict["title"] as? String,
@@ -268,6 +276,7 @@ class NotificationContent: Codable {
             url: dict["url"] as? String,
             payload: dict["payload"] as? [String: Any],
             etag: dict["etag"] as? String,
+            rolloverIntervalMinutes: rollover,
             deliveryStatus: dict["deliveryStatus"] as? String,
             lastDeliveryAttempt: lastDeliveryAttempt
         )