fix(android): support static reminder notifications and ensure channel exists

Static reminders scheduled via scheduleDailyNotification() with
isStaticReminder=true were being skipped because they don't have content
in storage - title/body are in Intent extras. Fixed by:

- DailyNotificationReceiver: Extract static reminder extras from Intent
  and pass to WorkManager as input data
- DailyNotificationWorker: Check for static reminder flag in input data
  and create NotificationContent from input data instead of loading from
  storage
- DailyNotificationWorker: Ensure notification channel exists before
  displaying (fixes "No Channel found" errors)

Also updated prefetch timing from 5 minutes to 2 minutes before notification
time in plugin code and web UI.

android/src/main/java/com/timesafari/dailynotification/DailyNotificationPlugin.kt

@@ -1286,9 +1286,9 @@ open class DailyNotificationPlugin : Plugin() {
                         reminderId = scheduleId
                     )
                     
-                    // Always schedule prefetch 5 minutes before notification
+                    // Always schedule prefetch 2 minutes before notification
                     // (URL is optional - native fetcher will be used if registered)
-                    val fetchTime = nextRunTime - (5 * 60 * 1000L) // 5 minutes before
+                    val fetchTime = nextRunTime - (2 * 60 * 1000L) // 2 minutes before
                     val delayMs = fetchTime - System.currentTimeMillis()
                     
                     if (delayMs > 0) {