refactor(notifications): update supporting classes for new timestamp model

- Remove setFetchTime() calls from DailyNotificationFetchWorker
- Remove setFetchTime() calls from DailyNotificationFetcher
- Update DailyNotificationMaintenanceWorker to use getFetchedAt()
- Update DailyNotificationMigration to use getFetchedAt()
- Align all classes with immutable fetchedAt timestamp approach
- Ensure consistent timestamp handling across the codebase

These changes support the new timestamp model where fetchedAt
is immutable and set at object creation time.

android/plugin/src/main/java/com/timesafari/dailynotification/DailyNotificationFetchWorker.java

@@ -385,7 +385,7 @@ public class DailyNotificationFetchWorker extends Worker {
             content.setId("timesafari_fallback_" + System.currentTimeMillis());
             content.setTitle("TimeSafari Update Available");
             content.setBody("Your community updates are ready. Tap to view offers, projects, and connections.");
-            content.setFetchTime(System.currentTimeMillis());
+            // fetchedAt is set in constructor, no need to set it again
             content.setScheduledTime(System.currentTimeMillis() + 30000); // 30 seconds from now
             
             return content;
@@ -448,7 +448,7 @@ public class DailyNotificationFetchWorker extends Worker {
                 fallbackContent.setSound(lastContent.isSound());
                 fallbackContent.setPriority(lastContent.getPriority());
                 fallbackContent.setUrl(lastContent.getUrl());
-                fallbackContent.setFetchTime(System.currentTimeMillis());
+                // fetchedAt is set in constructor, no need to set it again
                 
                 return fallbackContent;
             }
@@ -474,7 +474,7 @@ public class DailyNotificationFetchWorker extends Worker {
         content.setTitle("Daily Update");
         content.setBody("🌅 Good morning! Ready to make today amazing?");
         content.setScheduledTime(scheduledTime);
-        content.setFetchTime(System.currentTimeMillis());
+        // fetchedAt is set in constructor, no need to set it again
         content.setPriority("default");
         content.setSound(true);
         

android/plugin/src/main/java/com/timesafari/dailynotification/DailyNotificationFetcher.java

@@ -223,7 +223,7 @@ public class DailyNotificationFetcher {
             content.setTitle("Daily Update");
             content.setBody("Your daily notification is ready");
             content.setScheduledTime(System.currentTimeMillis() + TimeUnit.HOURS.toMillis(1));
-            content.setFetchTime(System.currentTimeMillis());
+            // fetchedAt is set in constructor, no need to set it again
             
             return content;
             
@@ -250,7 +250,7 @@ public class DailyNotificationFetcher {
             content.setTitle("Daily Update");
             content.setBody("Your daily notification is ready");
             content.setScheduledTime(System.currentTimeMillis() + TimeUnit.HOURS.toMillis(1));
-            content.setFetchTime(System.currentTimeMillis());
+            // fetchedAt is set in constructor, no need to set it again
             
             Log.d(TAG, "Network response parsed successfully");
             return content;
@@ -296,7 +296,7 @@ public class DailyNotificationFetcher {
         content.setTitle("Daily Update");
         content.setBody("🌅 Good morning! Ready to make today amazing?");
         content.setScheduledTime(System.currentTimeMillis() + TimeUnit.HOURS.toMillis(1));
-        content.setFetchTime(System.currentTimeMillis());
+        // fetchedAt is set in constructor, no need to set it again
         content.setPriority("default");
         content.setSound(true);
         

android/plugin/src/main/java/com/timesafari/dailynotification/DailyNotificationMaintenanceWorker.java

@@ -327,7 +327,7 @@ public class DailyNotificationMaintenanceWorker extends Worker {
                     return false;
                 }
                 
-                if (notification.getFetchTime() <= 0) {
+                if (notification.getFetchedAt() <= 0) {
                     Log.w(TAG, "Data integrity issue: Invalid fetch time");
                     return false;
                 }

android/plugin/src/main/java/com/timesafari/dailynotification/DailyNotificationMigration.java

@@ -177,7 +177,7 @@ public class DailyNotificationMigration {
                     values.put(DailyNotificationDatabase.COL_CONTENTS_PAYLOAD_JSON, 
                         gson.toJson(notification));
                     values.put(DailyNotificationDatabase.COL_CONTENTS_FETCHED_AT, 
-                        notification.getFetchTime());
+                        notification.getFetchedAt());
                     // ETag is null for migrated data
                     values.putNull(DailyNotificationDatabase.COL_CONTENTS_ETAG);